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1
Moens-Haenen, Greta. "Vibrato im Barock." Bärenreiter Verlag, 1987. https://slub.qucosa.de/id/qucosa%3A38344.
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Nandamudi, Srihimaja. "Aerodynamics of Vocal Vibrato." Bowling Green State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1499427478103556.
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Reese, Lorie. "Laryngeal-level amplitude modulation in vibrato /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1535.pdf.
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Besouw, Rachel Marijke van. "Representing the pitch of vibrato tones." Thesis, University of York, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441069.
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Reese, Lorie C. "Laryngeal-Level Amplitude Modulation in Vibrato." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/767.
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Research in vocal vibrato has established that vocal tract filtering is primarily responsible for the amplitude modulation (AM) present in Western classical vibrato. Using electroglottography (EGG) and the EGG speed quotient, which is sensitive to fluctuations in the amplitude of vocal fold vibration, AM was detected at the laryngeal (source) level, in addition to the subsequent AM which results from vocal tract filtering. Seventeen classically-trained opera singers sang vowels in three pitch and loudness conditions. EGG and microphone measurements of FM and AM and their rates, extents, and periodicity were made. Airflow was also measured, and the samples were rated by voice professors for vibrato consistency, speed, and width. Physiologic and acoustic data revealed that AM from vocal tract filtering, or the resonance-harmonics interaction (RHI) described by Horii and associates, was present throughout the vibrato samples. Laryngeal-level AM was also present throughout, with soft conditions having the highest mean extents. Singers with lower degrees of laryngeal-level AM were also those rated highest for vibrato consistency. Vibrato rate increased as pitch increased, and, to a lesser extent, as intensity increased. These findings document, in addition to the AM resulting from the RHI, the concurrent presence of laryngeal-level AM in a group of singers representing a range of training and experience.
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Secan, Stephen R. "Amplitude and frequency modulation in Oboe Vibrato." The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1407510603.
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Draiblate, Yoni. "HISTORY, EVOLUTION AND PEDAGOGY OF CELLO VIBRATO." Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/555692.
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Music PerformanceD.M.A.
On 9 April 1860, seventeen years before Thomas Edison invented the phonograph, a Parisian inventor named Leon Scott de Martinville invented the “phonautograph,” the first device capable of recording sound. In the demonstration recording produced by de Martinville, the listener hears the inventor singing a short section of the song “Au clair de la lune.” The recording lasts about ten seconds and is not of very good audio quality—it is full of interference and white noise, making it hard to decipher words. Technology has since evolved and improved to the point where we can examine the evolution of vibrato with relative ease, simply by listening to different recordings. When examining the question of cello vibrato prior to the second half of the 19th century with its technological innovations, however, we are left with a somewhat paradoxical question: “How did vibrato sound?“ This question is important for two reasons. First, through exploring the history of cello vibrato we may be able to make clearer inferences or, at the very least, establish more educated hypotheses, pertaining to general questions of sound and musical aesthetics throughout the centuries. Second, examining early cello technique and how it evolved can greatly help us understand the evolution of the left hand’s role in performance, particularly in the creation of vibrato. I am well aware that when it comes to historical performances prior to the introduction of quality recording technology, we can only deal with probabilities, never certainties, and we have no way of knowing what soloists and orchestral musicians sounded like, nor do we have a way to know what composers wished to hear. Since it is not possible to draw conclusions based on audio recordings prior to the end of the 19th century, I will explore the evolution of cello vibrato through close examination of early cello performance practice, as outlined in treatises and texts, as well as accounts by musicians who were key figures in developing and advancing playing techniques. While it will never be feasible to go back in time and hear this evolution for ourselves, it is possible to construct a better understanding of the use of vibrato prior to the second half of the 19th century. My aim in this paper is to better understand the evolution of cello vibrato, its origins, early techniques for producing it, and the influence of technique on vibrato over the years, mainly throughout Europe, in order to better answer this question: when did vibrato become an integral part of the cellist’s sound? Have cellists always used vibrato, and if so, did they use it continuously on all possible pitches? For the performing artist and teacher, it is highly beneficial to know the history and evolution of vibrato, and its role in the development of the cello sound over the years. Having this knowledge can have a direct effect on interpretation. By way of background, I will first discuss the origins of both the instrument and vibrato itself, in separate chapters.
Temple University--Theses
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Holmes, Sharee Oakes. "The Effects of Emotion on Acoustic Characteristics of Vocal Vibrato in Trained Singers." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3616.
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The purpose of this study was to investigate the effects of emotion on several key acoustic features of vibrato including vibrato rate, extent, and steadiness (measured by FM rate COV and FM extent COV). We hypothesized that intensity of emotion would have a significant effect on vibrato rate, extent, and periodicity, although the direction of these changes was undetermined. There were 10 participants, including eight females and two males, who were graduate student singers with high competency ratings. Each participant completed a series of tasks including sustained vowels at several pitch and loudness levels, an assigned song that was determined to have neutral emotion, and a personal selection that was selected because it included sections of intense emotion. Vowel tokens were averaged for each task, and measurements of mean f0, mean dB, FM rate, FM extent, FM rate COV and FM extent COV were calculated by task for each participant. Contrast analyses were performed comparing each task against the personal selection (high emotion) task. The results suggest that FM rate and FM rate COV may have been influenced by level of emotion, and FM extent, FM rate COV and FM extent COV were likely influenced by the performance nature of the task.
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Reidlinger, Christopher R. "Review and analysis of violin vibrato pedagogy with beginning violin students." Full text available online (restricted access), 2000. http://images.lib.monash.edu.au/ts/theses/Reidlinger.pdf.
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Manfredi, Zo Hurd. "Physical Problems in Vibrato Amongst First-year College Violinists: a Descriptive Study." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804848/.
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The purpose of this descriptive study was to first identify to what extent first-year college violinists physically struggle with the vibrato motion, and further, to identify physical problems within the motion that are contributing to their challenges during the learning process. The 16 participants in this study were chosen randomly from the College Music Society Directory of Music Faculties in Colleges and Universities (2013-2014 edition). Participants completed a questionnaire of 32 quantitative and qualitative questions addressing the vibrato of their 2013-2014 first-year violinists. 62% of participants’ first-year students had a physical problem with vibrato, 70% of participants’ students were working on correcting physical problems in vibrato during lessons. Participants also reported that 15% of their students were not able to create a vibrato motion at all. Almost all professors (n=15) indicated that students with a problematic vibrato were too tense in parts of the arm or hand and this negatively affected the motion and thus, the sound. Specific problems also included vibrato being too narrow, but rarely too wide, vibrato being too fast or too slow caused by tension, problems with when and how vibrato was being applied, problems with maintaining intonation before or during use of vibrato, and problems with not understanding the motion needed or imagining an intended sound. Most professors used movement terminology to describe physical problems with vibrato as well as aural problems with vibrato. Only a few professors discussed aural problems in vibrato using terminology depicting the sound. Participants revealed that the most commonly used types of vibrato amongst their first-year students were arm vibrato and a combination vibrato (use of wrist, arm and finger vibratos). Most participants also listed these combined parts of finger, wrist and arm in their own definitions of a good-sounding vibrato. Results from this study can be directed to the attention of classroom teachers, studio teacher and private instructors to these specific physical and aural problems before a student begins to study vibrato early in learning. Conclusions suggest possible ways in which the college or pre-college teacher can address these issues in students that have a problematic vibrato motion.
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Hinkley, Sandy Purdum. "Effects of Vibrato and Pitch-Varied Vocal Models on High School and Undergraduate Singers' Intonation, Intensity, and Use of Vibrato." Thesis, The Florida State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10261291.
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The purpose of this study was to investigate the effects of vibrato and pitch-varied vocal models on acoustic measures of high school and undergraduate singers’ vocal performance. Participants’ perception of vocal models was also examined to explore a possible relationship between perception and production. The following primary questions guided this research: 1) Is singers’ intonation affected by vibrato or pitch-varied vocal models? 2) Is singers’ vibrato rate affected by vibrato or pitch-varied vocal models? 3) Is singers’ vibrato extent affected by vibrato or pitch-varied vocal models? 4) Is singers’ intensity affected by vibrato or pitch-varied vocal models? Secondary questions under investigation were: 1) Do singers respond differently to vocal models of pitch patterns versus song phrases? 2) Does age and experience influence singers’ response? 3) Do singers perceive the differences in vocal models?
Participants (N = 76) were male (n = 38) and female (n = 38) singers who were undergraduates (n = 40) currently participating in a choral ensemble at the Florida State University or high school students (n = 36) currently enrolled in the choral program at a nearby high school. Participants responded to twelve vocal models of the same gender that were varied in melody, vibrato, and intonation conditions. Vocal models consisted of either a short pitch pattern ( sol-la-sol-fa-mi-re-do) or familiar song excerpt (Are You Sleeping?), both performed on the neutral syllable “tah.” Model melodies were sung in vibrato and minimal vibrato conditions, with each model having a specific 3rd and 5th scale degree that was presented in tune, sharp, or flat (mistuned pitches ± 25 cents relative to equal temperament). After responding to vocal models, participants were asked via written questionnaire if they perceived differences in vocal models and, if so, to describe them.
Audio recordings of participants’ responses were analyzed acoustically, with the specific 3rd and 5th scale degrees in each model analyzed for the dependent measures of intonation, vibrato rate, vibrato extent and intensity. Repeated measures analyses were conducted on the acoustic measures. An alpha level of .01 was used in all statistical tests. Written responses on the questionnaire were analyzed for keywords reflecting vocal technique or musical elements. Keywords were then identified and coded for frequency of response.
Significant differences in intonation were found, with responses to minimal vibrato models performed more flat than responses to vibrato models. Main effects were also found for gender, with male participants showing overall more flatness than females. Responses to pitch-varied models tended towards flat intonation, with flat models producing the greatest deviation particularly with male participants. Two interactions, both involving melody condition of models, also produced differences in intonation.
Significant differences in measures of vibrato rate and extent were also observed. Vibrato rates were faster and vibrato extents were wider in response to vibrato models. High school participants responded with similar vibrato rate and extent to both vibrato model conditions, whereas undergraduates responded with significantly faster vibrato rate and wider extent to vibrato models. Undergraduate vibrato rates were similar between genders, however high school males were significantly slower in vibrato rate than high school females.
Intensity results for both high school and undergraduate participants showed significantly higher intensity levels for 5th scale degrees than 3rds. High school males performed both scale degrees at similar intensity levels, while high school females sang 5ths with higher intensity. Significant differences in intensity were also found with undergraduates, with responses to vibrato models yielding higher intensity. Male undergraduates were found to sing with higher intensity in response to vibrato models, whereas females sang with similar intensity between vibrato-varied conditions. Interactions involving scale degree or melody condition of models also produced significant differences in intensity.
Analysis of written questionnaires showed that 71 (93%) participants perceived differences in models. The most frequently used keyword(s) was vibrato/straight tone, with 36 participants (51%) noting this as a perceived difference between models. Timbre/tone quality was the next most used word(s) by 13 participants (17%), followed by intonation/pitch used by 12 participants (15%). More males noticed changes in tone quality, intonation, and vowels than females, whereas the latter recognized vibrato changes more than males. Undergraduates perceived vibrato changes and intonation differences more than high school participants.
Many complex factors were thought to contribute to results of this study, including perception, experience, vocal development, and vocal production. While some findings support prior research, other results raise questions that warrant additional investigation. Implications and ideas for future inquiry are discussed.
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Mare, Minette. "Influential factors in the application of flute vibrato." Thesis, Stellenbosch : University of Stellenbosch, 2008. http://hdl.handle.net/10019.1/1718.
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Thesis (MMus (Music))--University of Stellenbosch, 2008.This thesis provides an overview of different aspects of the application of vibrato on the flute. Although it is a compilation of different viewpoints, it does not offer a conclusion as regards the ‘correct’ application of vibrato, due to the subjective nature of this phenomenon. The intention is that the reader will be able to reach his or her own conclusions and form new opinions regarding this subject. The focus is largely on the comparison of the production of vibrato on the flute with its production on other instruments. The aim is to examine the different choices involved in the production of vibrato when the flute is part of an ensemble and when it is a solo instrument. By learning more about other instruments’ timbres and production of vibrato, it enables flautists to adapt to different timbres in order to form sonorous ensembles. The physiological and scientific aspects of vibrato are also explored with the view to equip flautists with this knowledge. Thus, flautists will be able to listen to and analyse from a more critical and informed perspective how they themselves use vibrato and how other flautists use it. The main goal of this thesis is to provide enough information, opinions, studies and statistics to enable a flautist to make an informed decision concerning their choice and application of vibrato.
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Lester, Rosemary Anne. "Modulation of Voice Related to Tremor and Vibrato." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/325218.
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Modulation of voice is a result of physiologic oscillation within one or more components of the vocal system including the breathing apparatus (i.e., pressure supply), the larynx (i.e. sound source), and the vocal tract (i.e., sound filter). These oscillations may be caused by pathological tremor associated with neurological disorders like essential tremor or by volitional production of vibrato in singers. Because the acoustical characteristics of voice modulation specific to each component of the vocal system and the effect of these characteristics on perception are not well-understood, it is difficult to assess individuals with vocal tremor and to determine the most effective interventions for reducing the perceptual severity of the disorder. The purpose of the present studies was to determine how the acoustical characteristics associated with laryngeal-based vocal tremor affect the perception of the magnitude of voice modulation, and to determine if adjustments could be made to the voice source and vocal tract filter to alter the acoustic output and reduce the perception of modulation. This research was carried out using both a computational model of speech production and trained singers producing vibrato to simulate laryngeal-based vocal tremor with different voice source characteristics (i.e., vocal fold length and degree of vocal fold adduction) and different vocal tract filter characteristics (i.e., vowel shapes). It was expected that, by making adjustments to the voice source and vocal tract filter that reduce the amplitude of the higher harmonics, the perception of magnitude of voice modulation would be reduced. The results of this study revealed that listeners' perception of the magnitude of modulation of voice was affected by the degree of vocal fold adduction and the vocal tract shape with the computational model, but only by the vocal quality (corresponding to the degree of vocal fold adduction) with the female singer. Based on regression analyses, listeners' judgments were predicted by modulation information in both low and high frequency bands. The findings from these studies indicate that production of a breathy vocal quality might be a useful compensatory strategy for reducing the perceptual severity of modulation of voice for individuals with tremor affecting the larynx.
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Lamar, Jacquelyn B. (Jacquelyn Brown). "The History and Development of Vibrato Among Classical Saxophonists: A Lecture Recital Together with Three Recitals of Selected Works of A. Desenclos, L. Robert, J. Ibert, K. Husa, B. Heiden, R. Schumann and Others." Thesis, North Texas State University, 1986. https://digital.library.unt.edu/ark:/67531/metadc330729/.
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This study examines the history and development of vibrato among classical saxophonists as well as briefly summarizes the history of vibrato in general from its origins on string instruments, the voice and other wind instruments. An analysis of recordings of early saxophonists shows the approximate time period of incorporation of vibrato on the saxophone and the influences of performers and musical styles on its development. Pedagogical methods of performing vibrato on the saxophone are included as well as a discussion of saxophone vibrato styles. An exploration of vibrato as an expressive musical device is provided along with conclusions drawn concerning performance practice implications.
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Calitz, Wilken Craill. "A multidisciplinary study of the phenomenon of violin vibrato." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1792.
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Thesis (MMus (Music))--University of Stellenbosch, 2009Violin vibrato is the action by which a violinist periodically changes the frequency of a sustained note by moving the finger on the string, rapidly backwards and forwards. If it is artistically applied, it adds life, character and warmth to an otherwise dull sounding note. Although it has been used since the sixteenth century, very little research has been done on the reason why humankind would experience such periodic fluctuations as an object of beauty in violin performance. In answering the question, this study explores a variety of angles of approach in order to understand the phenomenon in its full context. The history, development and geographical origin of the technique are firstly discussed in a diachronic fashion and provide the background for the subsequent synchronic research on the physical nature of violin sound and violin vibrato. The vibrato rates and widths of four virtuosi are measured and compared to highlight the differences and individuality which are argued to be a contributing factor to the perception of beauty of the technique. It is established in the final chapter that the brain is stimulated more by sounds with periodic changes than those that are presented in the steady-state which cast some light on why vibrato may be experienced as an appreciated addition to sound. The thesis aims to present a unique view on the possibilities of interdisciplinary research of the phenomenon of violin vibrato. It further aims to present the research findings in a concise, logical, and systematic manner that could be of interest to both musician and scientist.
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Lee, Ka-won. "An investigation of left-hand vibrato technique on the violin." Full text available online (restricted access), 1999. http://images.lib.monash.edu.au/ts/theses/Lee.pdf.
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Gomes, Dos Santos Junior Osvaldo. "The Flute Inside-Out: Tracking Internal Movements in Flute Playing." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/17992.
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Analyses in the past have revealed that flute sound production is a complex procedure involving internal movements of the body. The larynx and pharynx in particular play a crucial role. Some authors, advocate for the abdominal muscles, while others, draw attention to the lips and the oral cavity. However, despite the various studies, the physiology of flute playing is limited by lack of empirically-derived information about what happens when a player carries out musical tasks. The present study is an empirical investigation of the role of the larynx and pharynx in flute playing from the perspective of a flute specialist. Specifically, the study aims to determine vocal fold involvement in vibrato, epiglottis movements, arytenoids and epiglottis involvement in articulation, and glottal aperture in tone and dynamics production (soft to loud, loud to soft). A detailed analysis of the relationship between standard flute techniques and the larynx and pharynx mechanisms is presented, making a significant contribution to the flute pedagogical literature. Two male and three female experienced players (referred to in the study as “the participants”) participated in a video-nasendoscopy procedure. The behaviour of the participants’ larynxes and pharynxes while playing a performance protocol specifically designed for this research was observed by a qualified speech pathologist. Specifically, the observer analysed true vocal fold adduction, false vocal fold adduction, laryngeal height, pharyngeal space, epiglottis movement, and arytenoid adduction. This study reveals that laryngeal/pharyngeal participation in flute playing is not limited to vibrato production or specific techniques, such as singing and playing or flutter tongue (tongue rolling effect while playing). The larynx plays a major role in producing flute tone and dynamics and should be considered by pedagogues, performers and health specialists. These findings can assist flute professionals in their daily practice, performances and teaching. Knowing the role of the larynx in vibrato, articulation, pitch control, and dynamics control, reveals a new tool for flute players to use with assurance when preparing any piece of the standard repertoire, or teaching a student.
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Douglas, David M. "An improved mechanical vibrato device for the electric bass guitar." Full text, Acrobat Reader required, 1998. http://viva.lib.virginia.edu/etd/theses/douglas98.pdf.
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Weber, Matthew J. (Matthew Joseph). "An Investigation of Selected Muscle Potential Activity in Violin/Viola Vibrato." Thesis, University of North Texas, 1995. https://digital.library.unt.edu/ark:/67531/metadc278616/.
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The purpose was to investigate muscle potential during the vibrato motion for successful, healthy violin/viola performers. Electromyography was used to analyze parameters of muscle potentials during performance of a standardized exercise. These parameters were (a) evidence of potentials, (b) patterns of potentials, and (c) timing relationships (24 muscles). This study also sought to replicate and expand performance data from previous studies. Procedures from three pilot studies were used to standardize collection of EMG data. Synchronized video recordings were used to determine vibrato speed and conduct motion analysis. EMG data processing prior to analysis included power spectrum analysis and rectification, low-pass filtering, and smoothing data. Motion analysis findings (£D) were 1.09 for the elbow joints and 3.25 for the wrist joints. which was an indication of range of motion, suggested much greater activity in muscles controlling wrist movement than those moving the elbow. The degree of muscle potential and control were generally related to distance from the vibrating hand. Forearm muscle groups (8) demonstrated the greatest evidence of potential (76.5%) and were 18.1% non-periodic. Muscles of the upper arm (7) were off 59.4% and 57.0% non-periodic. Upper arm muscles had greater individual differences. Muscles of the chest and back (9) were collectively inactive (89.1%) and non-periodic (73.3%). With timing relationships, the forearm muscles demonstrated consistent firing patterns. Inconsistent firing patterns were evident in the upper arm, and to a greater degree in the chest and back muscles. Based on evaluations of performer motion and muscle potentials, it was strongly implied that there are (a) distinct roles for various muscles during vibrato (control vs. stabilization/support), (b) significant differences in potential between variables of rest, playing position, and performing, (c) significant differences in potential between some fingers, and (d) no significant differences between violinists and violists. The vibrato motion appeared to be controlled primarily by forearm muscles.
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Jackson, Christopher Newlyn. "An Examination, Reinterpretation and Application of Selected Performance Practices in Four Motets of Luca Marenzio (1553-1599): Implications for a Modern Choral Performance Context." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1099%5F1%5Fm.pdf&type=application/pdf.
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KIM, YOU-SEONG. "A PEDAGOGICAL APPROACH TO THE TRILL IN SINGING." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1172621759.
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Saleiro, Clara Nora Vaz. "Estratégias de afinação baseadas em Intonation & Vibrato de Trevor Wye." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13629.
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Mestrado em Ensino de MúsicaEste projeto educativo incidiu sobre o tema da afinação, em particular, da flauta transversal. O projeto teve como base o método Intonation & Vibrato de Trevor Wye (Wye, 1983), a partir das ideias defendidas pelo autor e dos 24 pequenos estudos de afinação que propõe. Foi feito um levantamento dos diferentes temperamentos que existiram ao longo da história, as suas vantagens e desvantagens. Partindo do princípio de que também o temperamento igual não é perfeito e que, ao tocar um instrumento de afinação não-fixa, podemos corrigir certos intervalos mais importantes tendo em conta a posição que certas notas ocupam num determinado acorde/tonalidade, neste projeto foram abordadas duas estratégias de afinação. Numa das estratégias aplicadas os alunos aprenderam a afinar segundo as frequências de cada nota, utilizando como ferramenta de trabalho um afinador. Na outra estratégia os alunos aprenderam a afinar segundo as relações intervalares de cada tonalidade, tendo como base oitavas no registo grave de um piano. Procurou-se compreender o benefício em introduzir noções de afinação a partir do segundo ano de aprendizagem do instrumento, nível em que se encontravam todos os doze alunos em estudo. Pretendeu-se observar a reação dos alunos ao uso do afinador, bem como o desenvolvimento das suas capacidades auditivas ao longo do tempo.
This educative project focused particularly on the tuning of the flute. This project was based on Trevor Wye's method: Intonation & Vibrato (Wye, 1983), on the ideas supported by the author, and on 24 short tuning studies that he suggests. It was performed a search of the different temperaments that existed along history, and analysed their advantages and disadvantages. Assuming that an equal temperament is also not perfect and that, while playing non-fixed pitch instruments, one can correct specific important intervals knowing the position of certain music notes in a specific chord/tone, in this project two tuning strategies were used. At one strategy, the students learnt how to tune according to the frequency of each note using a tuner. On the other strategy, the students learnt how to tune according to the intervals between each tone, using octave notes in the very low register of the piano. It was intended to examine the benefits of teaching tuning strategies at the second year of the instrument studies, the educational level of the 12 students enrolled in this project. To observe the students' reactions to the use of a tuner, as well as the improvement of their hearing abilities throughout time.
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McLeod, Philip, and n/a. "Fast, accurate pitch detection tools for music analysis." University of Otago. Department of Computer Science, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090220.090438.
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Precise pitch is important to musicians. We created algorithms for real-time pitch detection that generalise well over a range of single �voiced� musical instruments. A high pitch detection accuracy is achieved whilst maintaining a fast response using a special normalisation of the autocorrelation (SNAC) function and its windowed version, WSNAC. Incremental versions of these functions provide pitch values updated at every input sample. A robust octave detection is achieved through a modified cepstrum, utilising properties of human pitch perception and putting the pitch of the current frame within the context of its full note duration. The algorithms have been tested thoroughly both with synthetic waveforms and sounds from real instruments. A method for detecting note changes using only pitch is also presented.
Furthermore, we describe a real-time method to determine vibrato parameters - higher level information of pitch variations, including the envelopes of vibrato speed, height, phase and centre offset. Some novel ways of visualising the pitch and vibrato information are presented.
Our project �Tartini� provides music students, teachers, performers and researchers with new visual tools to help them learn their art, refine their technique and advance their fields.
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Yang, Luwei. "Computational modelling and analysis of vibrato and portamento in expressive music performance." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/24857.
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Vibrato and portamento constitute two expressive devices involving continuous pitch modulation and is widely employed in string, voice, wind music instrument performance. Automatic extraction and analysis of such expressive features form some of the most important aspects of music performance research and represents an under-explored area in music information retrieval. This thesis aims to provide computational and scalable solutions for the automatic extraction and analysis of performed vibratos and portamenti. Applications of the technologies include music learning, musicological analysis, music information retrieval (summarisation, similarity assessment), and music expression synthesis. To automatically detect vibratos and estimate their parameters, we propose a novel method based on the Filter Diagonalisation Method (FDM). The FDM remains robust over short time frames, allowing frame sizes to be set at values small enough to accurately identify local vibrato characteristics and pinpoint vibrato boundaries. For the determining of vibrato presence, we test two alternate decision mechanisms-the Decision Tree and Bayes' Rule. The FDM systems are compared to state-of-the-art techniques and obtains the best results. The FDM's vibrato rate accuracies are above 92.5%, and the vibrato extent accuracies are about 85%. We use the Hidden Markov Model (HMM) with Gaussian Mixture Model (GMM) to detect portamento existence. Upon extracting the portamenti, we propose a Logistic Model for describing portamento parameters. The Logistic Model has the lowest root mean squared error and the highest adjusted Rsquared value comparing to regression models employing Polynomial and Gaussian functions, and the Fourier Series. The vibrato and portamento detection and analysis methods are implemented in AVA, an interactive tool for automated detection, analysis, and visualisation of vibrato and portamento. Using the system, we perform crosscultural analyses of vibrato and portamento differences between erhu and violin performance styles, and between typical male or female roles in Beijing opera singing.
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Carvalho, Mafalda Barradas. "Estratégias de ensino de vibrato na formação em flauta transversal em Portugal." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17694.
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Mestrado em Ensino de MúsicaNa preparação e execução de uma dada obra musical, o vibrato constitui um dos aspetos importantes a ter em conta pelo flautista. Contudo, o ensino e aperfeiçoamento desta componente técnica encontra-se por vezes ausente da sua formação básica e secundária, criando-lhe dificuldades no domínio e posterior aplicação do vibrato como elemento expressivo. O objetivo principal deste projeto educativo foi o de explorar estratégias para o ensino do vibrato em Portugal. Começou-se por realizar entrevistas semi-estruturadas a oito professores de flauta transversal de Conservatórios Oficiais de Música, para assim compreender como é ensinado o vibrato em Portugal. A segunda parte deste trabalho, relativa à Prática de Ensino Supervisionada, expõe a matriz da disciplina de flauta transversal desenvolvida para a Escola de Artes da Bairrada, seus elementos de avaliação, planificação e relatórios das aulas dadas e assistidas. Por fim é realizada uma avaliação e são apresentadas as atividades desenvolvidas ao longo do ano letivo de 2015/2016. Como resultado das entrevistas realizadas, é possível aferir que há dois consensos: o de que o vibrato deve ser usado pontualmente e não constantemente; e o de que o ensino do vibrato depende da evolução do aluno e do desenvolvimento da sua sonoridade, e não do grau específico em que se encontra da sua formação. No entanto, não existe uma unanimidade entre os entrevistados das estratégias a usar para a produção do vibrato. Verificou-se que metade dos participantes aprendeu vibrato por imitação e que todos os participantes acabam por pensar em vibrato em contextos diferentes, embora a maioria não trabalhe o vibrato em exercícios isoladamente mas sim em contexto de exercícios expressivos. Em relação à pedagogia do vibrato, a maioria dos professores ensina o vibrato sem ritmo, inserindo-o num contexto expressivo. Em relação à produção do vibrato 50% dos participantes afirma que o vibrato é produzido pelo diafragma, enquanto que 25% afirma que é pela garganta e os restantes dizem que é pela junção dos dois. Os resultados foram comparados com os resultados de outro estudo semelhante realizado na Turquia e nos EUA.
In the preparation and performance of a musical work, the vibrato constitutes an important aspect to be considered by flute players. Nonetheless, the teaching of this technical component is sometimes missing before college, creating difficulties in its mastering and subsequent application as an expressive element. The aim of this educative project was to develop strategies for the teaching of vibrato in Portugal. Firstly, were carried out semi-structured interviews to eight flute professors in official conservatories of music to analyze how vibrato is taught in Portugal. Secondly, relative to the Supervised Practical Music Teaching, it is presented the syllabus developed for the flute discipline of Escola de Artes da Bairrada, which includes the elements of evaluation, course calendar and the report of lectures given and assisted. Finally, it is presented an assessment of all activities conducted during the academic term 2015/2016. The results show that all the interviewers use the vibrato depending on the context and teach the vibrato technique depending on the students’ progress and their sonority development, rather than the specific school grade which the students are enrolled in. It was observed that half of the interviewers have been taught the vibrato technique by imitation, although they have learned not from specific exercises, but while studying melody studies. In turn, the majority of the professors interviewed teach the vibrato within an expressive context and not isolated with rhythmic exercises. However, the interviewers do not agree on the techniques to produce the vibrato, since 50% claim that the vibrato is produced using the diaphragm, 25% using the throat while the remaining claim that is produced from the combination of both. These results were then compared with the results of another study which took place both in Turkey and USA.
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Chen, Tzu Yun. "A Pedagogical Approach to Vibrato Styles for Advanced Cello Students and Their Teachers." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365642147.
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Remley, Jon Stephen. "The Preferred Oboe Vibrato: An Analysis of Pitch Modulation and Intensity Level Modulation." Thesis, University of North Texas, 1996. https://digital.library.unt.edu/ark:/67531/metadc278116/.
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The purpose of this study was to determine the pitch and intensity level characteristics found in the vibrati of preferred oboe players whose vibrato was ranked by a panel of experts. The investigation also sought to discover factors that distinguish the preferred oboe vibrato from vibrato that is less preferred.
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Moorcroft, Lynda. "Pre-Performance Practices: Breathing Imagery and Warm-Up For Singers." Thesis, The University of Sydney, 2011. http://hdl.handle.net/2123/7870.
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Research clarifying whether silent warm-up is possible and what constitutes a warmed-up voice is lacking. The acoustic correlates of a warmed-up voice are not clear, and perceptual correlates have centred on singers’ rather than both singers’ and listeners’ perceptions. This thesis therefore investigates acoustic and perceptual changes following vocal warm-up and breathing imagery, and whether breathing imagery may serve as a silent warm-up for singers. The literature review covers the acoustic and perceptual factors critical to optimal tone quality in singing, and the challenges of vocal assessment. It presents an historical survey of imagery and discusses the role of imagery in singing. It also investigates the relationship between optimal performance and vocal warm-up. As both imagery and warm-up for the voice are lacking thorough investigation, the review is supplemented with findings from sports psychology and sports medicine. In study 1, singers were recorded before and after three non-vocal 25 minute tasks. One task involved imagery of the breath directed upwards and downwards as far from the larynx as possible. Such imagery has played an important role in voice teaching since at least the 16th century. Another 25 minute task used Braille script as employed in the reading of music by the visually impaired. This provided the opportunity for the singer to engage in tactile, kinaesthetic and visual imagery related to music yet unrelated to breath function. A third task was a non-imagery breath-related activity that required the completion of a cloze passage about breath function for singers. In study 2, singers were recorded before and after a 25 minute vocal warm-up. The singers’ vocal signals were acoustically analysed for pre- to post-test changes in vibrato rate, vibrato extent and sound pressure level. Singer-subjects self-assessed their performances, and listener-judges perceptually rated the vocal samples presented in a fully randomised block design. Acoustic results for both breathing imagery and vocal warm-up produced three notable changes in vibrato rate: (i) more regularity in the cyclic undulations comprising the vibrato rate of a note, (ii) more stability in mean vibrato rates from one sustained note to the next, and (iii) a moderating of excessively fast and excessively slow mean vibrato rates for solos. The alternate imagery task based on Braille music code produced slower, less regular vibrato rates. This may have been due to the singers becoming too relaxed, as links are sometimes noted between imagery and relaxation. The non-imagery cloze passage task produced no significant change in vibrato from pre-test to post-test. Singers indicated that they sang better and felt warmed up after both the breathing imagery and vocal warm-up. The majority of listener-judges, however, concurred only in cases where the singer’s pre-test vibrato rate was either the fastest for the group, the slowest for the group or the most unstable for the group. Unlike vibrato rate, vibrato extent showed no consistent patterns of change acoustically as a result of any intervention. This thesis attempts to broaden our understanding of the relationships between imagery, warm-up and vibrato change. The findings support the use of vibrato analysis in the investigation of pedagogical practices. Furthermore, they indicate that change in the quality of vibrato, which impacts on tone quality, is central to both vocal warm-up and the long-standing use of directional imagery by singers. The findings of these studies may have direct bearing on teaching practice, physical and mental preparation, and the quality of vocal performance.
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Brown, Steven Franklin. "An Investigation of Perception of a Frequency Modulated Band Location of Pitch Within a Musical Vibrato." Thesis, North Texas State University, 1986. https://digital.library.unt.edu/ark:/67531/metadc331039/.
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The purpose of this study was to investigate aspects of pitch perception of auditors when presented with musical tones whose frequencies were modulated. Research problems were: estimation of the effect of musical training upon pitch perception; estimation of the effect of stimuli of differing tonal qualities and frequency ranges upon perception; and estimation of the effect of solo and ensemble performances upon pitch perception. Subjects for the study were thirty musicians and thirty nonmusicians. Subjects were students at North Texas State University and Paris Junior College who had volunteered for the study. A test containing thirty-six items was developed which required subjects to match a tone created by a sawtooth wave generator to a simultaneously presented musical tone performed with vibrato. Each subject was tested individually, and allowed three attempts to match each test item. After the third playing of each item, a reading was taken of the frequency selected by the subject, Using the split half method, reliability for the test was found to be .86 for nonmusicians and .88 for musicians.
ANOVA evaluation of responses of subjects indicated that there was a significant difference.in the location of pitch among musicians and nonmusicians, with musicians locating the pitch somewhat higher in the frequency spectrum than nonmusicians. Neither group located the pitch of modulated musical tones at the geometric mean of the modulation. Differences located in responses of the groups were consistant with regard to stimuli of varying frequency levels and timbres, and were unaffected by either solo or ensemble performance of the stimulus. Subsidiary findings indicated that among musicians no significant differences in pitch perception may be traced to the major performing instrument of the subject; differences in these subgroups and nonmusicians were consistant with the findings comparing musicians as "a whole and nonmusicians. Suggestions were made concerning application of the findings to musical training and concerning possibilities for further investigation in perception of pitch.
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Zinninger, Thomas. "An Analysis of Concert Saxophone Vibrato Through the Examination of Recordings by Eight Prominent Soloists." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1384428227.
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Adduci, Michael Douglas. "Dynamic Measurement of Intraoral Pressure and Sound Pressure With Laryngoscopic Characterization During Oboe Performance." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc103281/.
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Measurements of intraoral pressure (IOP) and sound pressure level (SPL) were taken of four oboists as they performed two sets of musical exercises: (1) crescendo-decrescendo from pp to ff and back to pp on the pitches D4, G4, C5 and A5, and (2) straight and vibrato performances of the same four pitches at mf. Video images of the vocal tract were also made using flexible fiberoptic nasoendoscopy (FFN). IOP and SPL data were captured in real time by the WinDaq®/Lite software package, with the dB meter located 8-9 inches in directly front of the oboe bell. The study yielded minimum and maximum values from 21.04 to 57.81 mm Hg and from 65.53 to 100.89 dB across all pitches examined. Discussion is included for the following topics: (1) the oboe’s sound envelope, or functional range of IOP and SPL values at different pitch levels, including the nonlinearity in the relationship between IOP and SPL on the oboe, (2) the static activation and kinetic maintenance thresholds for reed vibration, (3) the effect of vibrato on IOP/SPL, (4) the utilization of the vocal tract during execution of dynamic changes and vibrato, and (5) the impact of player experience on control of physical variables.
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Dalsant, Jessica. "Avaliação de duas ferramentas para a representação das variáveis acústicas implicadas no vibrato da flauta." Universidade Federal de Minas Gerais, 2011. http://hdl.handle.net/1843/AAGS-8L8P6X.
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This work investigated the flute vibrato, to determine which analytical tools that represent it in a more comprehensive way. Our aim is to use these tools to improve flute instrumental technic.
After considering previously published works on this topic, it has been decided to focus this investigation on the following vibrato acoustical parameters: extent, rate, deviation from the fundamental frequency (F0), regularity and wave shape, attack end ending of the note, use of the vibrato in the attack and ending of the note, noises/ ghost clouds, vibrato and spectral envelope evolution in time.
Two different types of tools were tested: first the spectrographic analysis program named SpectraPro, second an algorithm for the measure of vibratos fluctuations, proposed by the Physics and Electronics Departments of UFMG. Both tools are based based on the Fast Fourier Transform (FFT), but using different interfaces. Two types of samples have been evaluated: 1) long notes extracted from commercial recording 2) long notes from non commercial recordings, played live by different professional flutists in different dynamics and octaves. The same note was selected from a piece for solos flute, Syrinx, by Claude Debussy (1862-1918). The results of the application of these two tools indicated that the first one is more effective in measuring attack end ending of the note, noises/ ghost clouds, vibrato and spectral envelope evolution along the time, but its not precise in detecting rate and extent development in time. The second tool revealed to be more precise in measuring regularity, wave shape, rate and extent of F0.
The analysis of different acoustical parameters involved in vibrato allows us to understand what kind of changes happens in flutes sound and timbre.
To comprehend the various acoustical effects caused by vibrato in flute sound, means giving new technical and pedagogical possibilities for every flutist to improve the use, quality and flexibility of his/her vibrato and timbre. This can help to enrich the sound quality and the expressive possibilities of the flute.O presente trabalho investigou o vibrato na flauta transversal para determinar que ferramentas de análise acústica pudessem descrevê-lo de forma abrangente, tendo em vista sua aplicação no ensino dessa técnica instrumental. Depois de considerarem-se trabalhos previamente escritos sobre o assunto, resolveu-se focar a análise acústica do vibrato nos seguintes parâmetros acústicos: a profundidade, a taxa, o desvio da frequência fundamental, a modulação do envelope espectral, a regularidade e a forma da onda, o modo de ataque e conclusão da nota, os ruídos/nuvens fantasmas, a evolução no tempo. Esse conjunto de variáveis foi avaliado por dois processos de cálculo: primeiro, o programa de análise espectrográfica SpectraPro, segundo, o algoritmo proposto pelos departamentos de eletrônica e de física da UFMG. Ambos os processos são baseados na Transformada Rápida de Fourier (FFT), mas usam interfaces diferentes. Avaliaram-se dois tipos de amostras: 1) nota longa selecionada de gravações comerciais; 2) nota longa escolhida de gravações não comerciais feitas por diversos flautistas profissionais em diferentes oitavas e dinâmicas. A nota selecionada foi sempre a mesma e extraída da peça para flauta solo Syrinx, do compositor Claude Debussy (1862-1918). Os resultados da aplicação dessas ferramentas de medição do vibrato indicaram que o primeiro processo é mais efetivo na medição do modo de ataque e conclusão da nota, assim como, ruídos/nuvens fantasmas, evolução do vibrato no tempo e envelope espectral, mas não é adequado para rastrear a evolução temporal da taxa e da profundidade das modulações. O segundo processo calcula com maior precisão a regularidade, a forma da onda, a taxa e a profundidade da frequência fundamental (F0). A análise de diferentes variáveis acústicas envolvidas no vibrato permite-nos compreender mudanças que ocorrem no timbre e no som da flauta. Deste modo, conhecendo os diversos efeitos acústicos causados pelo vibrato na flauta, abrem-se possibilidades técnicas e didáticas, que ajudam o flautista a aprimorar o uso, a qualidade e a flexibilidade do seu vibrato, aumentando os recursos timbrísticos e expressivos determinantes da qualidade sonora do instrumento.
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Roiko-Jokela, Miia. "Laconisme de l’aile : Exploring modern flute techniques." Thesis, Kungl. Musikhögskolan, Institutionen för klassisk musik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kmh:diva-3182.
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This thesis introduces the modern flute techniques used in the solo flute piece Laconisme de l’aile by Kaija Saariaho. The purpose is to find ways to excecute the techniques so that they serve the music in the best way. The techniques are divided in five groups based on how they are excecuted: effects made with the mouth, changing the timbre, multiphonics, effects made by fingers and diffenent sounds by blowing. As an attachment there is a recording of the piece and how the techniques sound in the context. At the end of the process it has been evaluated, if the modern techniques help with the ordinary flute playing as well.A recording of Laconisme de l'aile by Kaija Saariaho
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Pool, Christopher Scott. "Observations of the larynx during vibrato production among professional bassoonists as indicated in experiments utilizing fiberoptic laryngoscopy." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/280737.
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The research presented here is an observational study of the larynx and its contributions to the production of vibrato on the bassoon. The process of vibrato production on the bassoon is a topic under much debate among its teachers and performers, with no standard guidelines in place for its execution. While most performers and teachers of the bassoon teach vibrato as a technique that uses abdominal pulsations of air to produce its effect, the role of the larynx has been largely ignored in its contribution to the process. This document compares vibrato production of the bassoonist to that of a trained vocalist, and contains references from the published literature on vocal, woodwind and bassoon vibrato. The experimental portion of this document observes the larynx of five professional bassoonists as they execute specific excerpts both with and without the use of vibrato. The observations of the larynx were conducted using the technique of fiberoptic laryngoscopy in the Speech and Hearing Department of the University of Arizona in November of 2002. Visual observations of videotaped examples and computer analysis of recorded sound waves using Praat software are included, which lead to conclusions that bassoon vibrato is controlled at the laryngeal level, primarily by the vocal folds.
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Faria, Priscila Oliveira. "Análise das variações do vibrato de cantoras líricas em duas cadências musicais de caráter alegre e triste." Universidade Federal de Minas Gerais, 2011. http://hdl.handle.net/1843/AAGS-8PPNFM.
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This paper presents a description of possible patterns of vibrato applied to the characters sad and happy. Using spectral analysis and an algorithm of spectral analysis of tremor and vibrato of the human voice developed in the Graduate Program in Electrical Engineering and Physical of UFMG, it aims the recognition of spectral analysis as a tool that enables differentiation of emotional characters involved in the performance of opera singers. The
methodology included the recording of 10 opera singers, performing two cadenzas, one of sad character and the other of happy character. Each cadenza was performed on the vowel [a] with an interjection, featuring an attack on the note (F4) with a duration of 4 seconds, after which the singer went down and closed it. The data were analyzed with the GRAM 5.7 software and algorithm analysis of tremor and vibrato, considering the variables: rate, extent, regularity and waveform in order to verify the general trends in each studied character. The conclusion was that the vibrato for the characters happy and sad present values of rate and extent acceptable according to the literature. The value of the rate for the character happy was not the greater than that for the character sad as expected. The regularity was prevalent in most singers studied. As for the waveform, the sinusoidal aspect predominated in both characters studied and three of the studied singers presented irregularities in the implementation of vibrato for the character sad. Concerning the attack and the termination of vibrato for the character happy, 60% (6) of the singers had a curve of the vibrato with an attack and a termination with an ascending form in performance, whereas, for the character sad, the curve begins and ends with a descending form for 40% (4) of the participants of the study. The general trends that distinguish one character from the other in this study is that the vibrato attack occurs for the character happy with an ascending form and descending form for the character sad.Este trabalho descreveu possíveis padrões de vibrato atribuíveis aos caráteres triste e alegre, utilizando a análise espectral e o algoritmo de análise do espectro do tremor e vibrato na voz humana desenvolvido no Programa de Pós-Graduação em Engenharia Elétrica e Física da UFMG, vislumbrando o reconhecimento da análise espectral como ferramenta que possibilite a diferenciação dos caráteres emotivos envolvidos na performance do cantor lírico. O método utilizado foi gravação da voz cantada de 10 cantoras líricas, executando duas cadências: uma de caráter triste e outra de caráter alegre. Cada cadência foi executada sobre a vogal [a] numa interjeição, apresentando um ataque na nota (Fá 4) com duração de 4 segundos, após a qual a cantora executou um movimento descendente e finalizou. Os dados foram analisados no software GRAM 5.7 e no algoritmo de análise do tremor e vibrato, contemplando as variáveis: taxa; profundidade; regularidade e forma de onda, a fim de verificar as tendências gerais em cada caráter estudado. Concluiu-se que o vibrato de caráter alegre e triste apresentam valores de taxa e profundidade aceitáveis conforme a literatura cujo valor da taxa no caráter alegre não foi maior em relação ao caráter triste conforme era esperado. A regularidade foi prevalente na maioria das cantoras estudadas. Quanto à forma de onda, o aspecto senoidal predominou em ambos os caráteres estudados e três das cantoras estudadas, apresentaram irregularidades na execução do vibrato de caráter triste. Em relação ao ataque e à terminação do vibrato de caráter alegre, encontramos que 60% (6) das cantoras tiveram a curva do vibrato com ataque e terminação de forma ascendente em sua performance e no caráter triste a curva se inicia e termina de forma descendente em 40% (4) das participantes do estudo. A tendência geral que diferencia um caráter do outro consiste no fato de o ataque do vibrato no caráter alegre ocorrer de forma ascendente e no caráter triste de forma descendente.
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Bunte, James. "A Player’s Guide to the Music of Ryo Noda: Performance and Preparation of Improvisation I and Mai." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282578051.
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Lachambre, Hélène. "Caractérisation de l'environnement musical dans les documents audiovisuels." Phd thesis, Université Paul Sabatier - Toulouse III, 2009. http://tel.archives-ouvertes.fr/tel-00457522.
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Actuellement, la quantité de musique disponible, notamment via Internet, va tous les jours croissant. Les collections sont trop gigantesques pour qu'il soit possible d'y naviguer ou d'y rechercher un extrait sans l'aide d'outils informatiques. Notre travail se place dans le cadre général de l'indexation automatique de la musique. Afin de situer le contexte de travail, nous proposons tout d'abord une brève revue des travaux réalisés actuellement pour la description automatique de la musique à des fins d'indexation : reconnaissance d'instruments, détermination de la tonalité, du tempo, classification en genre et en émotion, identification du chanteur, transcriptions de la mélodie, de la partition, de la suite d'accords et des paroles. Pour chacun de ces sujets, nous nous attachons à définir le problème, les termes techniques propres au domaine, et nous nous attardons plus particulièrement sur les problèmes les plus saillants. Dans une seconde partie, nous décrivons le premier outil que nous avons développé : une distinction automatique entre les sons monophoniques et les sons polyphoniques. Nous avons proposé deux nouveaux paramètres, basés sur l'analyse d'un indice de confiance. La modélisation de la répartition bivariée de ces paramètre est réalisée par des distributions de Weibull bivariées. Le problème de l'estimation des paramètres de cette distribution nous a conduit à proposer une méthode originale d'estimation dérivée de l'analyse des moments de la loi. Une série d'expériences nous permet de comparer notre système à des approches classiques, et de valider toutes les étapes de notre méthode. Dans la troisième partie, nous proposons une méthode de détection du chant, accompagné ou non. Cette méthode se base sur la détection du vibrato, un paramètre défini à partir de l'analyse de la fréquence fondamentale, et défini a priori pour les sons monophoniques. A l'aide de deux segmentations, nous étendons ce concept aux sons polyphoniques, en introduisant un nouveau paramètre : le vibrato étendu. Les performances de cette méthode sont comparables à celles de l'état de l'art. La prise en compte du pré-traitement monophonique / polyphonique nous a amenés à adapter notre méthode de détection du chant à chacun de ces contextes. Les résultats s'en trouvent améliorés. Après une réflexion sur l'utilisation de la musique pour la description, l'annotation et l'indexation automatique des documents audiovisuels, nous nous posons la question de l'apport de chacun des outils décrits dans cette thèse au problème de l'indexation de la musique, et de l'indexation des documents audiovisuels par la musique et offrons quelques perspectives.
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Gontevas, Maria. "Sångvibrato : En teknik av betydelse i sångundervisning?" Thesis, Kungl. Musikhögskolan, Institutionen för musik, pedagogik och samhälle, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kmh:diva-2959.
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När det gäller sångvibrato har lite forskning tidigare gjorts i ämnet, och när det gäller sångundervisning har jag i min egen erfarenhet aldrig haft någon sånglärare som talat om vibrato. Även bland tillfrågade sångkollegor, är det mycket sällsynt att de fått jobba med vibrato då de fått sångundervisning. Både på gymnasienivå och högskolenivå. Syftet var därför att ta reda på hur sånglärare arbetar med vibrato i sin sångundervisning. I den här uppsatsen har jag från ett kulturpsykolologiskt perspektiv och genom kvalitativa intervjuer undersökt huruvida sånglärare på gymnasium med estetiska program arbetar med vibrato och variation av vibrato med sina elever. Studiens forskningsfråga är: Vilka kulturella meningar ser några sånglärare med vibrato i sångundervisning? Resultaten varierade. Någon svarade att det inte var aktuellt i dennes undervisning, medan någon i sällsynta fall arbetade med vibratots vara eller icke vara i en sång. Överlag var vibratots mening dock inte något som prioriterades i sångundervisningen hos någon av de intervjuade sånglärarna. Resultatet visar att medvetenheten om vibratots mening och effekter på sången, oavsett genre, behöver väckas hos sånglärare.Bifogat finns en av mig inspelad version av en vers och refräng från gospellåten Keep Me av Tye Tribbet.
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Silva, Jose Eduardo de Carvalho. "Tremor e vibrato humanos: mediação de taxa, profundidade e regularidade no movimento demembros,na voz e no contrabaixo acústico." Universidade Federal de Minas Gerais, 2010. http://hdl.handle.net/1843/BUOS-8EUR7C.
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This work invetigated human tremor and vibrato. Algorithms for rate, extent and regularity measurements were evaluated in three signals: (i) tremor in upper limbs; (ii) spoken and sung voice; and (iii) long duration notes in the double bass. The study was carried out by measuring low frequency fluctuations (4-15 Hz) in the fundamental frequency series (F0) and in the signals envelope. Three techniques for amplitude and frequency modulation analysis were studied: analytic signal, Teagers operator, and Fourier analysis. The first two presented difficulties with multicomponent signals such as voice and music, while the Fourier method was more efficient. The mean values measured with Fourier analysis were (a) 4.7 Hz (rate) and 19.83 Hz (extent) for tremor in limbs; (b) 4.8 Hz (rate) and 3.98% (extent) for tremor in spoken voice; (c) 5.7 Hz (rate) and 3.12% (extent) for vibrato in sung voice; and (d) 5.0 Hz(rate) and 0.96% (extent) for vibrato in double bass. The Fourier method was not suitable to track the modulation rate and extent temporal behavior. To overcome this limitation, a technique was proposed based on the autocorrelation function to measure the similarity between F0 cicles over time. Results of application of this method to tremor/vibrato signal suggest that it can be used to measure the fundamental frequency regularity, but it still needs to be better evaluated in future works.Este trabalho investigou o tremor e o vibrato humanos. Foram avaliados algoritmos para a medição da taxa, da profundidade e da regularidade em três tipos de sinal: (i) tremor em membros superiores; (ii) voz falada e cantada e (iii) notas prolongadas no contrabaixo acústico. As análises foram feitas medindo-se flutuações de baixa freqüência (4-15 Hz), tanto na serie temporal da freqüência fundamental (F0) dos sinais quanto nas respectivas envoltórias. Foram investigadas três técnicas para analise de modulações em amplitude e em freqüência: sinal analítico, operador de Teager e análise de Fourier. Os dois primeiros apresentaram dificuldades para lidar com sinais multicomponentes, como é o caso da voz e música, enquanto o método de Fourier mostrou-se mais eficiente. Os valores médios obtidos com a análise de Fourier foram: (a) 4,7 Hz (taxa) e 19,83 Hz (profundidade) para tremor em membros; (b) 4,8 Hz (taxa) e 3,98% (profundidade) para tremor em voz falada; (c) 5,7 Hz (taxa) e 3,12% (profundidade) para vibrato em voz cantada; e (d) 5,0 Hz (taxa) e 0,96% (profundidade) para vibrato em contrabaixo. O método de Fourier não se mostrou adequado para rastrear a evolução temporal da taxa e da profundidade das modulações. Para tentar contornar esta limitação, foi proposta uma técnica baseada na função de autocorrelação que mede a similaridade entre ciclos da curva de F0 ao longo do tempo. Os resultados da aplicação deste método em sinais de tremor/vibrato sugerem que ele possa ser usado para medir a regularidade da freqüência fundamental, mas ainda é preciso avaliá-lo melhor em trabalhos futuros.
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Mueller, Rodney Alan. "The development and pilot testing of a hypermedia program to supplement undergraduate string techniques class instruction in upper string vibrato." Full text available online (restricted access), 1997. http://images.lib.monash.edu.au/ts/theses/Mueller.pdf.
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van, Stade Koenraad J. H. "Discovering Ideals of Expressivity and Artistry in 19th-Century Vocal Performance: Re-enacting Schumann’s Dichterliebe." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29588.
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The beginning of the 20th century saw the rise of modernist aesthetics which moulded modern performance practice. This change caused a steadfast distancing from the expressive practices of the late 19th century which were part of a continuum of practice going back to the 18th century or earlier. Recordings of singers, who in some cases were trained in the 1830s and 1840s, provide first-hand evidence of these late 19th-century practices and give insight into their embodied and tacit knowledge. Their singing sounds vastly different to the singing style generally heard today.
This thesis examines vocal performance practice information preserved in written sources and early recordings. The practices examined are portamento, tempo rubato (rhythmical asynchrony and tempo modification), vibrato and messa di voce. The main goal is the re-enactment of the singing style from the decades preceding the recording era (extrapolating back to the 1850s). This has entailed a comprehensive analysis of a greater body of historical recordings than previously undertaken. Comparison between these recordings and written sources (annotated scores, instructive editions, vocal treatises, technical methods, concert reviews, correspondence, and biographies) provides in-depth understanding of practices and their application. For the practical application of this evidence, I have adopted a cyclical research process (recording emulation and experimental implementation of performance practice data), which has been used in previous research. Outcomes are presented in a practice-led case study: a recording of Schumann’s Dichterliebe (1840), a reimagining of the song cycle as it might have sounded in the decades immediately following its composition.
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Ferrell, Matthew August. "Perspectives on Choral and Solo Singing: Enhancing Communication Between Choral Conductors and Voice Teachers." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/494.
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Concepts of choral and solo singing diverge among the masses of pedagogues, teachers, and conductors who have differing opinions about healthy vocal technique and training. These differences have generated tension within some university music programs, with choral faculty and voice faculty sometimes on opposing sides. This document presents answers from professional singers who engage in choral and solo singing while maintaining a healthy vocal technique. All subjects interviewed for this document were asked to speak in detail to vocal adjustments made to sing in different styles. In addition, they were asked to identify any vocal faults that may arise from improper vocal production. The goal of this document is to lay grounds for valuable discussion regarding the opposing perspectives found in some academic circles with regard to proper vocal technique and training for choral and solo singing.
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Záleská, Veronika. "Využití vibrodiagnostiky v soudním inženýrství." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-232846.
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This thesis deals with the measurement and evaluation of vibration on selected parts of car. Part of the work is devoted to the theory of vibration and noise, which includes, among others, presentations of common disorders of machine parts in terms of vibration. In the practical part of the work were performed out measurements described here and the results analyzed. Last part is in short devoted to the possibilities of using a similar measurement in forensic engineering.
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Wilcocks, Gerda Reinette. "Improving tone production on the flute with regards to embouchure, lip flexibility, vibrato and tone colour, as seen from a classical music perspective." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-09132007-163345/.
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Mitchell, Helen Frances. "Defining vocal quality in female classical singers: pedagogical, acoustical and perceptual studies." Thesis, The University of Sydney, 2005. http://hdl.handle.net/2123/710.
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The technique of 'open throat' is a pedagogical concept transmitted through the oral tradition of singing. This thesis explored the pedagogical perceptions and practices of 'open throat' using empirical methodologies to assess technical skill and associated vocal quality. In the first study (Mitchell, Kenny, Ryan, & Davis, 2003), we assessed the degree of consensus amongst singing pedagogues regarding the definition of, and use in the singing studio of the technique called 'open throat.' Results indicated that all fifteen pedagogues described 'open throat' technique as fundamental to singing training and were positive about the sound quality it achieved, especially in classical singing. It was described as a way of maximising pharyngeal space or abducting the false vocal folds. Hypotheses generated from pedagogical beliefs expressed in this first study were then tested acoustically (Mitchell & Kenny, 2004a, 2004b). Six advanced singing students sang in two conditions: 'optimal' (O), using maximal open throat, 'sub-optimal' (SO), using reduced open throat and loud sub-optimal (LSO) to control for the effect of loudness. From these recordings, acoustic characteristics of vibrato (Mitchell & Kenny, 2004b) and energy distribution (Mitchell & Kenny, 2004a) were examined. Subsequent investigations of the vibrato parameters of rate, extent and onset, revealed that extent was significantly reduced and onset increased when singers did not use the technique. As inconsistent vibrato is considered indicative of poor singing, it was hypothesized that testing the energy distribution in these singers' voices in each condition would identify the timbral changes associated with open throat. Visual inspection of long term average spectra (LTAS) confirmed differences between O and SO, but conventional measures applied to long term average spectra (LTAS), comparing energy peak height [singing power ratio (SPR)] and peak area [energy ratio (ER)] were not sensitive to the changes identified through visual inspection of the LTAS. These results were not consistent with the vibrato findings and suggest that conventional measures of SPR and ER are not sufficiently sensitive to evaluate LTAS. In the fourth study, fifteen expert listeners consistently and reliably identified the presence of open throat technique with 87% accuracy (Mitchell & Kenny, in press). In the fifth study, LTAS measurements were examined with respect to the perceptual ratings of singers. There was no relationship between perceptual rankings of vocal beauty and acoustic rankings of vocal quality (Kenny & Mitchell, 2004, in press). There is a vast literature of spectral energy definitions of good voice but the studies in this thesis have indicated that current acoustic methods are limited in defining vocal quality. They also suggest that current work in singing has not sufficiently incorporated perceptual ratings and descriptions of sound quality or the relationship between acoustic and perceptual factors with pedagogical practices.
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Mitchell, Helen Frances. "Defining vocal quality in female classical singers: pedagogical, acoustical and perceptual studies." University of Sydney. Australian Centre for Applied Research in Music Performance, 2005. http://hdl.handle.net/2123/710.
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The technique of �open throat� is a pedagogical concept transmitted through the oral tradition of singing. This thesis explored the pedagogical perceptions and practices of �open throat� using empirical methodologies to assess technical skill and associated vocal quality. In the first study (Mitchell, Kenny, Ryan, & Davis, 2003), we assessed the degree of consensus amongst singing pedagogues regarding the definition of, and use in the singing studio of the technique called �open throat.� Results indicated that all fifteen pedagogues described �open throat� technique as fundamental to singing training and were positive about the sound quality it achieved, especially in classical singing. It was described as a way of maximising pharyngeal space or abducting the false vocal folds. Hypotheses generated from pedagogical beliefs expressed in this first study were then tested acoustically (Mitchell & Kenny, 2004a, 2004b). Six advanced singing students sang in two conditions: �optimal� (O), using maximal open throat, �sub-optimal� (SO), using reduced open throat and loud sub-optimal (LSO) to control for the effect of loudness. From these recordings, acoustic characteristics of vibrato (Mitchell & Kenny, 2004b) and energy distribution (Mitchell & Kenny, 2004a) were examined. Subsequent investigations of the vibrato parameters of rate, extent and onset, revealed that extent was significantly reduced and onset increased when singers did not use the technique. As inconsistent vibrato is considered indicative of poor singing, it was hypothesized that testing the energy distribution in these singers� voices in each condition would identify the timbral changes associated with open throat. Visual inspection of long term average spectra (LTAS) confirmed differences between O and SO, but conventional measures applied to long term average spectra (LTAS), comparing energy peak height [singing power ratio (SPR)] and peak area [energy ratio (ER)] were not sensitive to the changes identified through visual inspection of the LTAS. These results were not consistent with the vibrato findings and suggest that conventional measures of SPR and ER are not sufficiently sensitive to evaluate LTAS. In the fourth study, fifteen expert listeners consistently and reliably identified the presence of open throat technique with 87% accuracy (Mitchell & Kenny, in press). In the fifth study, LTAS measurements were examined with respect to the perceptual ratings of singers. There was no relationship between perceptual rankings of vocal beauty and acoustic rankings of vocal quality (Kenny & Mitchell, 2004, in press). There is a vast literature of spectral energy definitions of good voice but the studies in this thesis have indicated that current acoustic methods are limited in defining vocal quality. They also suggest that current work in singing has not sufficiently incorporated perceptual ratings and descriptions of sound quality or the relationship between acoustic and perceptual factors with pedagogical practices.
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Mallikarjuna, Trishul. "Towards expressive melodic accompaniment using parametric modeling of continuous musical elements in a multi-attribute prediction suffix trie framework." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37190.
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Elements of continuous variation such as tremolo, vibrato and portamento enable dimensions of their own in expressive melodic music in styles such as in Indian Classical Music. There is published work on parametrically modeling some of these elements individually, and to apply the modeled parameters to automatically generated musical notes in the context of machine musicianship, using simple rule-based mappings. There have also been many systems developed for generative musical accompaniment using probabilistic models of discrete musical elements such as MIDI notes and durations, many of them inspired by computational research in linguistics. There however doesn't seem to have been a combined approach of parametrically modeling expressive elements in a probabilistic framework. This documents presents a real-time computational framework that uses a multi-attribute trie / n-gram structure to model parameters like frequency, depth and/or lag of the expressive variations such as vibrato and portamento, along with conventionally modeled elements such as musical notes, their durations and metric positions in melodic audio input. This work proposes storing the parameters of expressive elements as metadata in the individual nodes of the traditional trie structure, along with the distribution of their probabilities of occurrence. During automatic generation of music, the expressive parameters as learned in the above training phase are applied to the associated re-synthesized musical notes. The model is aimed at being used to provide automatic melodic accompaniment in a performance scenario. The parametric modeling of the continuous expressive elements in this form is hypothesized to be able to capture deeper temporal relationships among musical elements and thereby is expected to bring about a more expressive and more musical outcome in such a performance than what has been possible using other works of machine musicianship using only static mappings or randomized choice. A system was developed on Max/MSP software platform with this framework, which takes in a pitched audio input such as human singing voice, and produces a pitch track which may be applied to synthesized sound of a continuous timbre. The system was trained and tested with several vocal recordings of North Indian Classical Music, and a subjective evaluation of the resulting audio was made using an anonymous online survey. The results of the survey show the output tracks generated from the system to be as musical and expressive, if not more, than the case where the pitch track generated from the original audio was directly rendered as output, and also show the output with expressive elements to be perceivably more expressive than the version of the output without expressive parameters. The results further suggest that more experimentation may be required to conclude the efficacy of the framework employed in relation to using randomly selected parameter values for the expressive elements. This thesis presents the scope, context, implementation details and results of the work, suggesting future improvements.
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Kotinda, Giovanni Iamin. "Absorvedor dinâmico de vibração tipo lâmina vibrante." Universidade Federal de Uberlândia, 2005. https://repositorio.ufu.br/handle/123456789/14912.
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Conselho Nacional de Desenvolvimento Científico e TecnológicoThis work is dedicated to the design of a vibrating blade dynamic vibration absorber (ADVLV), which is composed by a blade that is subjected to an initial traction T , and contains a concentrated mass m that is fixed at a given position d along the blade. These three parameters can be adjusted so that the ADVLV is tuned. For this aim, a finite element model of the system was built, leading to a design methodology for the absorber. Also, design of experiment techniques were performed to obtain the most interesting configurations for the system, both for the computational and experimental models. Special care was taken with respect to the boundary conditions for the finite element model, so that the dynamic responses could correspond to the physical aspects of the problem, accordingly. Besides, an experimental prototype was constructed and tested under laboratory conditions. The experimental results were compared with those obtained from mathematical simulation. From this comparison, it was concluded that the finite element model had to be updated in such a way that experimental results could match. A vibrating string dynamic vibration absorber (ADVCV) was also studied. However, this DVA configuration presented two anti-resonant frequencies due to the coupling of the first vibration mode along the horizontal and vertical directions with a concentrated mass. Another phenomenon that was observed is the tridimensional motion of the vibrating string around its equilibrium position, leading to an ellipsoid-shape movement when a harmonic excitation whose frequency coincides with the primary system resonance frequency is applied to the system. This way, the ADVCV is not able to attenuate the vibration amplitude of the primary system satisfactorily. It is worth mentioning that the proposed ADVLV presents a good dynamic behavior besides a wide frequency range along which the DVA can be tuned. Besides, the present vibration absorbing device is simple and can be easily connected to the primary system both to mechanical and civil engineering structures.
Este trabalho aborda o projeto de um absorvedor dinâmico de vibrações do tipo lâmina vibrante (ADVLV), sendo este constituído por uma lâmina sujeita a uma tração inicial T com uma massa concentrada m que pode ser fixada em uma posição d da lâmina. Este três parâmetros podem ser alterados a fim de se obter a sintonia do ADVLV. Para realizar o estudo deste, foi elaborado um modelo de elementos finitos do sistema, permitindo assim obter a metodologia para seu projeto. Também foram usadas técnicas de planejamento de experimento para obter as melhores configurações, tanto para os ensaios computacionais como experimentais. Foram tomados cuidados na criação das condições de contorno do modelo de elementos finitos, a fim de se obter respostas que representem adequadamente os aspectos físicos do problema. Também foi construído um protótipo e este foi ensaiado no laboratório. Os resultados obtidos foram comparados com os obtidos através da simulação computacional. A partir desta comparação verificou-se a importância de realizar ajustes no modelo de elementos finitos para adequar este à realidade. Também foi estudado o absorvedor dinâmico de vibração do tipo corda vibrante. Entretanto este ultimo ADV apresentou duas freqüências de anti-ressonância devido ao acoplamento do primeiro modo de vibrar nas direções horizontal e vertical da corda vibrante com uma massa concentrada. Outro fenômeno observado foi o movimento tridimensional da corda vibrante em torno da sua posição de equilíbrio, resultando uma forma semelhante a um elipsóide de revolução quando uma excitação harmônica com freqüência igual à freqüência de ressonância do sistema primário é aplicada sobre o sistema. Desta forma, o ADVCV não consegue cumprir a sua função de atenuar a amplitude de vibração da estrutura primária, sendo, portanto, completamente ineficiente neste caso. O ADVLV, proposto neste trabalho, apresentou comportamento dinâmico satisfatório, além de uma grande faixa de freqüências na qual o ADV pode ser sintonizado. Este dispositivo é de fácil construção e acoplamento, tanto a sistemas mecânicos, como a estruturas de construção civil.
Mestre em Engenharia Mecânica
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Rossignol, Stéphane. "Segmentation et indexation des signaux sonores musicaux." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2000. http://tel.archives-ouvertes.fr/tel-00010732.
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Ce travail concerne la segmentation et l'indexation des signaux sonores musicaux. Trois niveaux de segmentation interdépendants sont définis, correspondant chacun à un niveau de description du son différent.1) Le premier niveau de segmentation, appelé << sources >>, concerne la distinction entre la parole et la musique. Les sons considérés peuvent provenir par exemple de bandes-son de films ou d'émissions radiophoniques.
Des fonctions d'observation sont étudiées, qui ont pour objectif de mettre en évidence les propriétés différentes du signal de parole et du signal de musique. Plusieurs méthodes de classification ont été étudiées. Les performances du système avec des signaux réels sont discutées.
2) Le deuxième niveau de segmentation, appelé << caractéristiques >>, concerne ce type d'index : silence/son, voisé/non voisé, harmonique/inharmonique, monophonique/polyphonique, avec vibrato/sans vibrato, avec trémolo/sans trémolo. La plupart de ces caractéristiques donnent lieu à des fonctions d'observation utilisées par le troisième niveau de segmentation.
La détection du vibrato, l'estimation de ses paramètres (fréquence et amplitude) et sa suppression du trajet de la fondamentale ont été particulièrement étudiées. Un ensemble de techniques sont décrites. Les performances de ces techniques avec des sons réels sont discutées.
Le vibrato est supprimé du trajet de la fondamentale original afin d'obtenir une ligne mélodique << lissée >>. Alors, ce nouveau trajet de la fondamentale peut être utilisé pour la segmentation en notes (troisième niveau de segmentation) des extraits musicaux, et peut aussi être utilisé pour des modifications de ces sons.
La détection du vibrato est opérée seulement si, lors du premier niveau de segmentation, c'est la source << musique >> qui a été détectée.
3) Le troisième niveau de segmentation concerne la segmentation en << notes ou en phones ou plus généralement en parties stables >>, suivant la nature du son considéré : instrumental, voix chantée, parole, son percussif...
L'analyse est composée de quatre étapes. La première consiste à extraire un grand nombre de fonctions d'observation. Une fonction d'observation est d'autant plus appropriée qu'elle présente des pics grands et fins quand des transitions surviennent et que sa moyenne et sa variance restent petites pendant les zones stables. Trois types de transitions existent : celles en fréquence fondamentale, celles en énergie et celles en contenu spectral. En deuxième lieu, chaque fonction d'observation est automatiquement seuillée. En troisième lieu, une fonction de décision finale, correspondant aux marques de segmentation, est construite à partir des fonctions d'observation seuillées. Finalement, pour les sons monophoniques et harmoniques, la transcription automatique est effectuée. Les performances du système avec des sons réels sont discutées.
Les données obtenues pour un certain niveau de segmentation sont utilisées par les niveaux de segmentation de numéro d'ordre supérieurs afin d'améliorer leurs performances.
La longueur des segments donnés par le niveau de segmentation en << sources >> peut être de quelques minutes. La longueur des segments donnés par le niveau de segmentation en << caractéristiques >> est communément plus petite : elle est disons de l'ordre de quelques dizaines de secondes. La longueur des segments donnés par le niveau de segmentation en << zones stables >> est le plus souvent inférieure à une seconde.
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Caldas, Tiago Reis [UNESP]. "Desenvolvimento de um instrumento portátil para detectar falha em rolamento de motor de indução, pela técnica do envelope, usando um DSP de 16 bits e a transformada de Hilbert." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/97047.
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Em um ambiente industrial é responsabilidade da manutenção cumprir com as necessidades específicas de cada processo produtivo. Basicamente é necessário aumentar a disponibilidade e a confiabilidade dos equipamentos. Este trabalho apresenta o desenvolvimento de um equipamento portátil para identificar precocemente problemas em rolamentos, utilizando o método conhecido como técnica de envelope ou HFRT (High Frequency Resonance Technique). A técnica de envelope é justificada como sendo a mais indicada para detectar defeitos de único ponto em rolamentos. Os principais componentes dos circuitos são apresentados, justificando a utilização. A programação do microcontrolador dsPIC33 foi feita em C, utilizando o MPLAB IDE da Microchip. Após a aquisição do sinal de aceleração, são aplicados alguns filtros e transformadas, sobretudo a transformada de Fourier com 1024 pontos amostrados em 5ksps, para cálculo do espectro da vibração. Como interface homemmáquina (IHM), foram utilizados um teclado e um mostrador gráfico que apresenta as amplitudes referentes às frequências de falha. Com base nos espectros e nas amplitudes, é possível comparar com os valores das normas vigentes (ISO 2372, ISO 3945 ou ISO 10816), gerando por fim um laudo sobre o estado dos rolamentos do motor elétrico. O protótipo foi testado utilizando os sinais gerados pelo Matlab/Simulink e apresentou um ótimo desempenho
In an industrial environment is the responsibility of maintenance keeping the specific needs of each production process. Basically it is necessary to increase the availability and reliability of equipment. This work presents the development of a portable device to identify problems early on bearings, using the method known as technical envelope or HFRT (High Frequency Resonance Technique). The envelope technique is justified as being more suitable for detecting single point defects in bearing. The main components of the circuits are presented, justifying the use. The dsPIC33 microcontroller programming was done in C using Microchip's MPLAB IDE. After the acquisition of the acceleration signal, some filters are processed and applied , especially the Fourier transformed of 1024 points sampled in 5ksps to calculate the spectrum of vibration. As human interface (HMI), a keyboard and a graphical display were used which shows the amplitudes related to the failure frequency. Based on the spectra and the amplitudes, it is possible to compare the values of standards (ISO 2372, ISO 3945 or ISO 10816), finally originating a report about the state of electric motor bearings. The prototype was tested using the signals originated by Matlab / Simulink and it has presented a great performance