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1
Iglehart, Frank, Cheryl DeConde Johnson, and Stephen Wilson. "Classroom acoustics and the inclusion of hard of hearing children, helping the data be heard." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A169. http://dx.doi.org/10.1121/10.0011003.
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Data on speech perception in children have led to acoustic accommodations in built schools for children with typical hearing but, despite compelling data, not for children who are hard of hearing. The ways to meet the acoustic needs of hard of hearing children are well researched and established in standards. After many years, however, the message is still not disseminating to architects, school districts, and building officials, and thus rarely makes its way into classroom construction. To help bring classroom accessibility to hard of hearing children, a team from the fields of acoustical engineering, architecture, and audiology is using speech perception data and computer simulations to promote inclusion in school design. This multi-year, multi-disciplinary effort began with earlier federal and foundation fundings for research on speech perception in hard of hearing children, which led to development of a new voluntary acoustic standard for schools by the American National Standards Institute. The goal of this work now is to get this standard into the hands of architects and school districts, and ultimately into building codes to have classroom acoustics designed for all students including those hard of hearing.
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Howe, Bruce M., and James H. Miller. "Acoustic Sensing for Ocean Research." Marine Technology Society Journal 38, no. 2 (June 1, 2004): 144–54. http://dx.doi.org/10.4031/002533204787522811.
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Ocean observatories have the potential to examine the physical, chemical, biological, and geological parameters and processes of the ocean at time and space scales previously unexplored. Acoustics provides an efficient and cost-effective means by which these parameters and processes can be measured and information can be communicated. Integrated acoustics systems providing navigation and communications and conducting acoustic measurements in support of science applications are, in concept, analogous to the Global Positioning System, but rely on acoustics because the ocean is opaque to electromagnetic waves and transparent to sound. A series of nested systems is envisioned, from small- to regional- to basin-scale. A small number of acoustic sources sending coded, low power signals can service unlimited numbers of inexpensive receivers. Drifting and fixed receivers can be tracked accurately while collecting ocean circulation and heat content data (both point and integral data), as well as ambient sound data about wind, rain, marine mammals, seismic T-phases, and anthropogenic activity. The sources can also transmit control data from users to remote instruments, and if paired with receivers enable two-way acoustic communications links. Acoustic instrumentation that shares the acoustic spectrum completes the concept of integrated acoustics systems. The ocean observations presently in the planning and implementation stages will require these integrated acoustics systems.
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Shetty, Vishwas, Steven M. Lulich, Pertti Palo, and Abeer Alwan. "Development of vowel acoustics and subglottal resonances in American English-speaking children: A longitudinal Study." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A286. http://dx.doi.org/10.1121/10.0016294.
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Acoustic analysis of typically developing elementary school-aged (prepubertal) children’s speech has been primarily performed on cross-sectional data in the past. Few studies have examined longitudinal data in this age group. For this presentation, we analyze the developmental changes in the acoustic properties of children’s speech using data collected longitudinally over four years (from first grade to fourth grade). Four male and four female children participated in this study. Data were collected once every year for each child. Using these data, we measured the four-year development of subglottal acoustics (first two subglottal resonances) and vowel acoustics (first four formants and fundamental frequency). Subglottal acoustic measurements are relatively independent of context, and average values were obtained for each child in each year. Vowel acoustics measurements were made for seven vowels (i, ɪ, ɛ, æ, ʌ, ɑ, u), each occurring in two different words in the stressed syllable. We investigated the correlations between the children’s subglottal acoustics, vowel acoustics, and growth-related variables such as standing height, sitting height, and chronological age. Gender-, vowel-, and child-specific analyses were carried out in order to shed light on how typically developing speech acoustics depend on such variables. [Work supported, in part, by the NSF.]
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Pita, Antonio, Francisco J. Rodriguez, and Juan M. Navarro. "Analysis and Evaluation of Clustering Techniques Applied to Wireless Acoustics Sensor Network Data." Applied Sciences 12, no. 17 (August 26, 2022): 8550. http://dx.doi.org/10.3390/app12178550.
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Exposure to environmental noise is related to negative health effects. To prevent it, the city councils develop noise maps and action plans to identify, quantify, and decrease noise pollution. Smart cities are deploying wireless acoustic sensor networks that continuously gather the sound pressure level from many locations using acoustics nodes. These nodes provide very relevant updated information, both temporally and spatially, over the acoustic zones of the city. In this paper, the performance of several data clustering techniques is evaluated for discovering and analyzing different behavior patterns of the sound pressure level. A comparison of clustering techniques is carried out using noise data from two large cities, considering isolated and federated data. Experiments support that Hierarchical Agglomeration Clustering and K-means are the algorithms more appropriate to fit acoustics sound pressure level data.
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DeCourcy, Brendan J., and Ying-Tsong Lin. "Identifying the presence and importance of 3D acoustic effects in New England Shelf Break Acoustics experiment data." Journal of the Acoustical Society of America 153, no. 3_supplement (March 1, 2023): A217. http://dx.doi.org/10.1121/10.0018703.
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During the 2021 New England Shelf Break Acoustics (NESBA) experiments, a real-time physical oceanographic and ocean acoustic modeling effort sought to predict planned acoustic transmissions between a network of moorings in situ. While positive comparisons between simulated acoustics and hydrophone observation were made during field experiments, updates to ocean environment models post-cruise have improved the model and data agreement. Of importance to this real-time modeling effort is to use the disagreement between acoustic simulation and acoustic data to estimate model environment errors. By identifying spatial locations of likely error in the modeled sound speed, in situ acoustic simulations can identify acoustically significant locations to perform measurements of ocean water state properties such as temperature and salinity, as well as marine geological features. This presentation will focus on comparison efforts, extracting model environment error estimates, and explore the influence of 3D effects on this process. [This research is supported by the Office of Naval Research.]
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Stewens, Thomas, Christian Adams, Alexander Pfaff, and Christopher Morschel. "Augmented reality for visualization of complex vibroacoustic data sets." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 2 (February 1, 2023): 5820–26. http://dx.doi.org/10.3397/in_2022_0863.
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As technical solutions become more and more complex, analyzing and understanding them must become easier. Especially abstract or perception-biased fields, such as acoustics, can benefit from displaying the behavior of a noise radiating structure in an understandable manner. How can the acoustic properties of a technical component or a system be displayed in such an understandable way? Due to the current advances in technology regarding the mixed reality spectrum, the HoloLens2 was chosen as the hardware component to run an application and display structural properties visually. The application is required to display enough data to convey the information without impeding user experience. The application is divided into subprojects. Each subproject is developed and tested in a separate environment. After verification the subprojects were implemented. AR-visualization reduces the necessary effort to understand the structure's acoustic behavior. Furthermore, explicit knowledge of acoustics is not required to understand the application. In the future, this application can be expanded with additional features such as auralization or a live feed of structures.
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Martinez, Veronica, Charles Anderson, Carrie Wall, and Elizabeth Jimenez. "Centralized data repositories: NOAA’s National Archives for Marine Acoustic Data." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A234. http://dx.doi.org/10.1121/10.0011172.
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The NOAA National Centers for Environmental Information maintains two marine acoustic archives for the long-term stewardship of globally collected water-column sonar and passive acoustic data. These vast datasets are collected across NOAA and academia for a wide range of scientific objectives. The archives document the datasets using standards-driven metadata and preserve them on long-term storage systems. Users can discover, query, and access archived data using the archives’ web-based map viewers. Further, cloud-based access to 200 + TB through the NOAA Big Data Program enables free and immediate download of desired data and allows users to bring processing routines to large volumes of data—from simple statistical analyses to artificial intelligence. Cloud-based tools are being developed in collaboration with our partners in the ocean acoustic community to visualize and analyze data in the archives. This allows researchers of varying backgrounds to easily understand the quality and content of these complex data. Providing free access to data archives and facilitating the utility of these data increases the potential for researchers to address new questions that will advance the field of marine ecosystem acoustics.
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Barnard, Andrew, and Daniel A. Russell. "The graduate program in acoustics at Penn State." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A124. http://dx.doi.org/10.1121/10.0015762.
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The Graduate Program in Acoustics at Penn State offers graduate degrees (M.Eng., M.S., Ph.D.) in Acoustics, with courses and research opportunities in a wide variety of subfields. Our 820 alumni are employed around the world in a wide variety of military and government labs, academic institutions, consulting firms, and consumer audio and related industries. Our 40+ faculty from several disciplines conduct research and teach courses in structural acoustics, nonlinear acoustics, architectural acoustics, signal processing, aeroacoustics, biomedical ultrasound, transducers, computational acoustics, noise and vibration control, acoustic metamaterials, psychoacoustics, and underwater acoustics. Course offerings include fundamentals of acoustics and vibration, electroacoustic transducers, signal processing, acoustics in fluid media, sound and structure interaction, digital signal processing, experimental techniques, acoustic measurements and data analysis, ocean acoustics, architectural acoustics, noise control engineering, nonlinear acoustics, outdoor sound propagation, computational acoustics, biomedical ultrasound, flow induced noise, spatial sound and three-dimensional audio, and the acoustics of musical instruments. This poster highlights faculty research areas, laboratory facilities, student demographics, successful graduates, and recent enrollment and employment trends for the Graduate Program in Acoustics at Penn State.
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Lammert, Adam, Michael Proctor, and Shrikanth Narayanan. "Interspeaker Variability in Hard Palate Morphology and Vowel Production." Journal of Speech, Language, and Hearing Research 56, no. 6 (December 2013): 1924–33. http://dx.doi.org/10.1044/1092-4388(2013/12-0211).
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Purpose Differences in vocal tract morphology have the potential to explain interspeaker variability in speech production. The potential acoustic impact of hard palate shape was examined in simulation, in addition to the interplay among morphology, articulation, and acoustics in real vowel production data. Method High-front vowel production from 5 speakers of American English was examined using midsagittal real-time magnetic resonance imaging data with synchronized audio. Relationships among hard palate morphology, tongue shaping, and formant frequencies were analyzed. Simulations were performed to determine the acoustical properties of vocal tracts whose area functions are altered according to prominent hard palate variations. Results Simulations revealed that altering the height and position of the palatal dome alters formant frequencies. Examinations of real speech data showed that palatal morphology is not significantly correlated with any formant frequency but is correlated with major aspects of lingual articulation. Conclusion Certain differences in hard palate morphology can substantially affect vowel acoustics, but those effects are not noticeable in real speech. Speakers adapt their lingual articulation to accommodate palate shape differences with the potential to substantially affect formant frequencies, while ignoring palate shape differences with relatively little acoustic impact, lending support for acoustic goals of vowel production.
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Douglass, Alexander S., John Ragland, and Shima Abadi. "Overview of distributed acoustic sensing technology and recently acquired data sets." Journal of the Acoustical Society of America 153, no. 3_supplement (March 1, 2023): A64. http://dx.doi.org/10.1121/10.0018174.
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Fiber optic distributed acoustic sensing (DAS) is a recent innovation utilized primarily in the seismic community for measuring seismic acoustics signals at low frequencies (single digit Hz and below). The technique utilizes strain rates in a fiber optic cable, observed via the backscatter of light pulses, to measure the acoustic field. Recently, the capabilities of this technology to measure higher frequency acoustic fields (10s to 100s of Hz) have been explored. Low frequency marine mammals calls at ∼20 Hz and ship noises have been successfully recorded, and a recent experiment demonstrated the capability to record up to ∼500 Hz. This talk provides an overview of DAS technology and introduces two recent experiments for studying water column acoustics with DAS. A 4-day experiment conducted in November 2020 as part of the Ocean Observatories Initiative (OOI) provides data along two fiber optic cables extending west from the coast of Oregon by 65 km and 95 km, reaching depths of 590 m and 1575 m, respectively. DASCAL22, a recent experiment from October 2022, simultaneously recorded data using DAS at 2 kHz sampling rate on a cable extending 3.54km at ∼100 m depth and multiple moored hydrophones placed close to the DAS cable, allowing direct comparison between a new and existing technology.
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Ahmed, Umair, Fakhre Ali, and Ian Jennions. "Signal Processing of Acoustic Data for Condition Monitoring of an Aircraft Ignition System." Machines 10, no. 9 (September 19, 2022): 822. http://dx.doi.org/10.3390/machines10090822.
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Degradation of the ignition system can result in startup failure in an aircraft’s auxiliary power unit. In this paper, a novel acoustics-based solution that can enable condition monitoring of an APU ignition system was proposed. In order to support the implementation of this research study, the experimental data set from Cranfield University’s Boeing 737-400 aircraft was utilized. The overall execution of the approach comprised background noise suppression, estimation of the spark repetition frequency and its fluctuation, spark event segmentation, and feature extraction, in order to monitor the state of the ignition system. The methodology successfully demonstrated the usefulness of the approach in terms of detecting inconsistencies in the behavior of the ignition exciter, as well as detecting trends in the degradation of spark acoustic characteristics. The identified features proved to be robust against non-stationary background noise, and were also found to be independent of the acoustic path between the igniter and microphone locations, qualifying an acoustics-based approach to be practically viable.
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Hjellvik, Vidar, Dag Tjøstheim, and Olav Rune Godø. "Can the precision of bottom trawl indices be increased by using simultaneously collected acoustic data? The Barents Sea experience." Canadian Journal of Fisheries and Aquatic Sciences 64, no. 10 (October 1, 2007): 1390–402. http://dx.doi.org/10.1139/f07-101.
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Acoustic data are recorded continuously during the winter survey for demersal fish in the Barents Sea. This paper presents a method for using the information from the acoustic recordings between trawl stations in an attempt to increase the precision of the trawl estimate. The method is related to the double-sampling regression estimation, in which information from a frequently sampled auxiliary variable (e.g., acoustics) that is correlated with the main variable (e.g., trawl) is used for the purpose of increasing the precision in the estimate of the population mean of the main variable. The version presented here allows for additional explanatory variables and for autocorrelation in the main and auxiliary variables. However, when applied to the Barents Sea data, only a minor variance reduction is obtained. The main reasons for this are a high autocorrelation in the acoustic data and a relatively low correlation between trawl and acoustics on trawl stations. Another unexpected result is that the acoustic density during trawling is significantly higher than between trawl stations.
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Sari, Laina Hilma, and Zulfian Zulfian. "An Assessment of Room Acoustics Performance of Baiturrahman Grand Mosque." Elkawnie 6, no. 1 (June 30, 2020): 24. http://dx.doi.org/10.22373/ekw.v6i1.5420.
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Abstract : Acoustical design as part of the audio comfort influences the architectural design strategy of a mosque significantly. As belonging to the speech room criteria, a mosque should meet some acoustic room requirements to deliver the solemnness to the worshipper during the prayer. Concerning this, the study aims to assess the indoor acoustics performance of Baiturrahman Grand Mosque, Banda Aceh. Baiturrahman grand mosque is an important place of worship for Acehnese and becoming a landmark of Banda Aceh City. The mosque which contains a lot of history of Aceh was built in heavy construction, i.e. concrete wall, marble coated floor, and concrete dome ceiling. Due to its significance, the room acoustics of the mosque as the primary design considerations in a speech room type is evaluated. The acoustics parameters estimated are Noise Criteria (NC), Sound Pressure Level (SPL), Reverberation Time (RT), and Rapid Speech Transmission Index (RASTI). The background noise was recorded for delivering the noise criteria and being the primary data carried out in the acoustic simulation. The study utilised CATT-Acoustic v7.2 software for simulating predicting SPL, RT, and RASTI.Abstrak : Desain akustik merupakan bagian dari parameter audio yang mempengaruhi desain arsitektur masjid secara signifikan. Masjid termasuk dalam kategori speech room yang harus memenuhi beberapa persyaratan akustik ruang untuk dapat menghadirkan kekhusyukan kepada jamaah selama sholat. Penelitian ini bertujuan untuk menilai kinerja akustik dalam ruangan Masjid Raya Baiturrahman, Banda Aceh. Masjid Raya Baiturrahman adalah tempat ibadah yang penting bagi orang Aceh dan menjadi simbol Kota Banda Aceh. Masjid yang memuat banyak sejarah Aceh ini terbuat dari dinding beton, lantai berlapis marmer, dan langit-langit kubah beton. Pada studi ini, parameter akustik ruang yang dievaluasi adalah Kriteria Kebisingan (NC), Tingkat Tekanan Suara (SPL), Waktu Gema (RT), dan Indeks Transmisi kecepatan Bicara (RASTI). Kebisingan latar belakang direkam untuk memberikan kriteria kebisingan dan menjadi data primer yang dilakukan dalam simulasi akustik. Studi ini menggunakan perangkat lunak CATT-Acoustic v7.2 untuk mensimulasikan prediksi SPL, RT, dan RASTI.
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LI, FAN, XINYI GUO, TAO HU, and LI MA. "ACOUSTIC TRAVEL-TIME PERTURBATIONS DUE TO SHALLOW-WATER INTERNAL WAVES IN THE YELLOW SEA." Journal of Computational Acoustics 22, no. 01 (March 2014): 1440003. http://dx.doi.org/10.1142/s0218396x14400037.
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Internal waves in shallow-water cause variations in sound speed profiles and lead to acoustic travel-time perturbations. In summer 2007, a combined acoustics/physical oceanography experiment was performed to study both the acoustical properties and the ocean dynamics of the Yellow Sea. The internal waves were recorded by the thermistor arrays. The receiving hydrophone array is enabled to monitor the acoustic travel-time fluctuations over the internal wave activities. It is shown that the activity of high frequency internal waves (having 3–6 min period) dominated the travel time perturbation. In this paper, we compare the data of high frequency internal wave with acoustic travel-time perturbation data and analyze the correlation between them. A simple relation between the modal travel-time perturbation and the displacement of the thermocline is developed which might be useful for monitoring purposes.
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Iglehart, Frank. "Speech perception and deaf and hard of hearing children in the classroom: A multidisciplinary effort in the United States to bring data and standards to architects, school districts, and into building codes." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 6 (February 1, 2023): 1932–35. http://dx.doi.org/10.3397/in_2022_0272.
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This presentation will discuss efforts by a multidisciplinary team to overcome the notable lack of progress in the United States in acoustic accommodations for deaf and hard of hearing children in the classroom. Data collected through research efforts by members of this team, and by others, demonstrate the benefits of appropriate acoustics for all children and especially those deaf and hard of hearing. These efforts have resulted in a voluntary standard in classroom acoustics specifically for deaf and hard of hearing children by the American National Standards Institute. This standard, however, is not reaching built classrooms. This team representing the fields of acoustics, architecture and audiology is using speech perception data and new computer simulations to increase awareness of the need for classroom acoustic standards in building codes to accommodate deaf and hard of hearing children.
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Woszczyk, Wieslaw, Aybar Aydin, and Ying-Ying Zhang. "Virtual Acoustics, better than the real thing? Considering the creative side." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A181. http://dx.doi.org/10.1121/10.0015962.
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Once room acoustical reflections data are extracted from a physical space or a model, and are encapsulated in a 3D impulse response, they can be used to render immersive sound fields in real time. A range of possibilities then opens for creative use of acoustics in music. A skilled virtual acoustics designer-engineer may rebalance digital signals representing the room response to situate player and listener on the stage or at the back of the auditorium, may modify and arrange temporal segments to re-imagine the aural dimensions of the space, and apply gain and directional placement to shape the impression of immersive presence, adapting acoustics to musicians’ creative needs. In the process of building an idealized acoustical environment for the music, techniques of sound reinforcement and of rendering room acoustics are combined to balance presence with ambience and to deliver a sensation of acoustical power with lift-off. The means exist to move beyond acoustical realism into fictionalized acoustics.
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Putra, Azma, D. Hafizah, M. Y. Yaakob, and Mohd Jailani Mohd Nor. "Study on the Use of Micro-Perforated Panel to Improve Acoustic Performance in Mosque." Applied Mechanics and Materials 393 (September 2013): 971–75. http://dx.doi.org/10.4028/www.scientific.net/amm.393.971.
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Most activities in mosque such as Friday prayer and the sermon by an Imam require clarity of speech. Unfortunately, this speech intelligibility performance is often poor due to initial design of a mosque. This paper presents assessment of the indoor acoustics of a mosque. Acoustical properties such as reverberation time, clarity and early decay time are obtained from simulation data using CATT indoor acoustic software. The study started with an empty mosque with no acoustic treatment. Acoustic green absorbers using micro-perforated panel (MPP) are then introduced to improve the acoustic performance. The application of MPP is still rare for mosque and is expected to replace the typical porous absorber. The effect of the panel size, location and frequency range of sound absorption are simulated and the results are discussed.
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Koslow, J. Anthony. "The role of acoustics in ecosystem-based fishery management." ICES Journal of Marine Science 66, no. 6 (April 8, 2009): 966–73. http://dx.doi.org/10.1093/icesjms/fsp082.
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Abstract Koslow, J. A. 2009. The role of acoustics in ecosystem-based fishery management. – ICES Journal of Marine Science, 66: 966–973. For more than half a century, acoustics has been a leading tool in fishery stock assessment. Today, the need for ecosystem-based management poses new challenges for fishery scientists: the need to assess the ecological relationships of exploited species with predators and prey and to predict the potential effects of climate variability and climate change on recruitment. No research tool is likely to prove as effective as acoustics in meeting these needs, if it is properly integrated into interdisciplinary research programmes involving ecology and oceanography, as well as fisheries. Integration of data from acoustics and ocean-observation, as well as from satellites and other high-resolution oceanographic mapping tools, is likely to lead to major advances in fishery oceanography. New developments in acoustic technology, such as three-dimensional, multibeam acoustics, and shelf-scale acoustic mapping, may also lead to significant advances. Notwithstanding these developments, critical biases and shortcomings of acoustic methods that were noted 50 years ago remain with us. For example, the identification of insonified biota and single-target discrimination remains relatively primitive. Progress is urgently needed in these basic underpinnings of the acoustic method.
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Rittmueller, Steve. "Discussion of impacts of measurement error in architectural acoustics performance specifications." Journal of the Acoustical Society of America 153, no. 3_supplement (March 1, 2023): A305. http://dx.doi.org/10.1121/10.0018941.
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Customers for acoustic products need manufacturers and professionals to provide performance specifications to allow informed design decisions. Acoustic professionals rely upon standard tests and special labs to quantify products. Data published by the ASTM for E90 shows that an STC rating for a single construction can have a variability range of up to 7 points. Being logarithmic, this equates to a sound pressure range of more than 2×, larger than 100%. The log nature of many acoustical performance metrics hides this from most. This large variability causes challenges for the architectural acoustics community. The primary negative impact: customers do not trust the acoustical ratings manufacturers provide. This is not an issue of the manufacturers providing inaccurate information, it is an issue of under-reported and incomplete understanding of the uncertainty in the metrics themselves. For perspective, NRC measured the Young’s Modulus of OSB material to have a mean of 6.8 × 109 and a standard deviation of 1.5 × 108 (Ref: NRC IR-766, Table 22). This yields a measurement error of 3.8%. It is simple to account for this in the design process. If the metric has an uncertainty as large as the acoustic metrics, the standard paradigm for accounting for error not only breaks down, it incentivizes bad actors: cherry picking, lab shopping, etc. More open acknowledgement of the measurement error in architectural acoustic metrics would increase the confidence customers have in them and would allow designers to make more informed decisions.
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Mann, David A. "Managing the passive acoustics data deluge." Journal of the Acoustical Society of America 125, no. 4 (April 2009): 2617. http://dx.doi.org/10.1121/1.4783970.
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Simmons, Andrea Megela, Chen Ming, and Laura N. Kloepper. "Estimating chorusing activity by quantifying total acoustic energy." JASA Express Letters 2, no. 8 (August 2022): 081201. http://dx.doi.org/10.1121/10.0013351.
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Passive acoustics provides a powerful method for localizing vocalizing animals and estimating species abundance. A passive acoustics method previously used to census dense populations of flying bats is applied here to estimate chorusing activity of male bullfrogs vocalizing against anthropogenic noise. There are significant links between manual counts of the numbers of advertisement call notes and automatically detected notes and two measures of acoustic energy. These data provide a foundation for the use of acoustic energy measures to census vocal activity in different habitats.
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Oyekola, Peter, William Rogers, James Fedorka, Nathaniel Colemon, Nathan Woodard, Mehedi Al-Barkat, and Mohan Rao. "Evaluation and optimization of acoustics of a multipurpose room to improve speech intelligibility." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 264, no. 1 (June 24, 2022): 695–704. http://dx.doi.org/10.3397/nc-2022-800.
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The work presented in this paper was conducted as part of a student project in a senior course on Noise Control at Tennessee Tech. The project involved improving the acoustics of the multipurpose room in the university student center. There were repeated concerns regarding the poor acoustics conditions related with speech and intelligibility caused by excessive reverberations in the room. In order to solve this issue, an examination of the complete sound field in the room including reverberation time have been investigated with the aim of proposing solutions to improve the acoustics for future use. The evaluation of the room was done with both software simulation and experimental data obtained from on-site visit measurements. A comparison between the simulated and experimental data is presented and served as the basics for the analytical solutions necessary for acoustic optimization. Furthermore, renderings of possible mounting locations of acoustic panels with their specification have been provided based on the commercially available panels and cost consideration.
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Mooney, T. Aran, Lucia Di Iorio, Marc Lammers, Tzu-Hao Lin, Sophie L. Nedelec, Miles Parsons, Craig Radford, Ed Urban, and Jenni Stanley. "Listening forward: approaching marine biodiversity assessments using acoustic methods." Royal Society Open Science 7, no. 8 (August 2020): 201287. http://dx.doi.org/10.1098/rsos.201287.
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Ecosystems and the communities they support are changing at alarmingly rapid rates. Tracking species diversity is vital to managing these stressed habitats. Yet, quantifying and monitoring biodiversity is often challenging, especially in ocean habitats. Given that many animals make sounds, these cues travel efficiently under water, and emerging technologies are increasingly cost-effective, passive acoustics (a long-standing ocean observation method) is now a potential means of quantifying and monitoring marine biodiversity. Properly applying acoustics for biodiversity assessments is vital. Our goal here is to provide a timely consideration of emerging methods using passive acoustics to measure marine biodiversity. We provide a summary of the brief history of using passive acoustics to assess marine biodiversity and community structure, a critical assessment of the challenges faced, and outline recommended practices and considerations for acoustic biodiversity measurements. We focused on temperate and tropical seas, where much of the acoustic biodiversity work has been conducted. Overall, we suggest a cautious approach to applying current acoustic indices to assess marine biodiversity. Key needs are preliminary data and sampling sufficiently to capture the patterns and variability of a habitat. Yet with new analytical tools including source separation and supervised machine learning, there is substantial promise in marine acoustic diversity assessment methods.
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Guo, Lixian, and Dan Zhao. "Effects of temperature difference and operating pressures on heat-driven acoustic characteristics and nonlinear behaviors in a looped tube traveling wave thermoacoustic engine." Journal of the Acoustical Society of America 154, no. 4_supplement (October 1, 2023): A286. http://dx.doi.org/10.1121/10.0023544.
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In this work, the output heat-driven acoustic characteristics and dynamic thermal-fluid flow fields in a looped-tube traveling-wave thermoacoustic engine (TWTAE) are numerically investigated. Emphasis is placed on optimizing acoustic power output from the TWTAE by varying its operating pressure and temperature difference across the regenerator. For this, a time domain full-scale 3-D traveling-wave TAE model is developed, and then validated by comparing with those results obtained from the experimental data available in the literature. The present results indicate that the acoustic pressure oscillations and the acoustic power are increased with increased operating pressure of the working gas. Furthermore, nonlinear acoustics and flow dynamics in the heat-driven acoustic and flow fields of the TWTAE such as vortex generation around the regenerator and Gedeon streaming are observed. Considering the comprehensive acoustic characteristics, the optimal heat-driven acoustic power output, and thermo-acoustics energy conversion efficiency are achieved, as the working air pressure is set to 0.4 MPa. Increasing the temperature difference across the regenerator can further improve the acoustic power output from the TWTAE. In summary, the present 3-D model can be used as a design tool for predicting and optimizing looped tube traveling-wave TAE performances with detailed thermos-fluid dynamics and acoustics characteristics.
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Russell, Daniel A., and Andrew Barnard. "Graduate education in acoustics at a distance from Penn State." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A125. http://dx.doi.org/10.1121/10.0015763.
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The Graduate Program in Acoustics at Penn State has been providing access to graduate level education in Acoustics for remote students across the country and around the world for more than 35 years. This poster summarizes the distance education Acoustics program from Penn State by showcasing student demographics, capstone paper topics, enrollment statistics and trends, and the success of our graduates. Our distance education program is offered in conjunction with our resident graduate program—course lectures are broadcast as a live stream over Zoom from a hybrid multimedia classroom allowing remote students to engage with faculty and students during live lectures; archived recordings are available for offline viewing afterward. Courses offered for distance education students include: fundamentals of acoustics and vibration, electroacoustic transducers, signal processing, acoustics in fluid media, sound and structure interaction, digital signal processing, aerodynamic noise, acoustic measurements and data analysis, ocean acoustics, architectural acoustics, noise control engineering, nonlinear acoustics, outdoor sound propagation, computational acoustics, flow induced noise, spatial sound and 3D audio, marine bioacoustics, and acoustics of musical instruments. Distance Education students can earn the M.Eng. in Acoustics degree remotely by completing 30 credits of coursework and writing a capstone paper.
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Abadi, Shima, William S. Wilcock, and Brad P. Lipovsky. "Detecting hydro-acoustic signals using Distributed Acoustics Sensing technology." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A201. http://dx.doi.org/10.1121/10.0016027.
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Distributed Acoustic Sensing (DAS) is a relatively new technology that transforms fiber optic cables, typically used for telecommunications, into dense sensor arrays, capable of meter-scale recordings up to ∼100 km. The interest in these technologies for ocean exploration and monitoring has risen in recent years. These systems enable continuous and highly sensitive measurements of both temporal and spatial acoustic data. In this presentation, we use data recorded during a 4-day DAS experiment on the twin cables of the Ocean Observatories Initiative (OOI) Regional Cabled Array (RCA) extending off central Oregon. We demonstrate the capabilities of DAS in recording a wide range of acoustic signals including the 20-Hz call of fin whales, the 15-Hz calls and harmonics of the Northeast Pacific blue whale, and ship noises. We use beamforming and the time difference of arrival (TDOA) algorithm to find the bearing and the location of the signal of interest. We also explain the DAS array response and its sensitivity to paths arriving parallel or perpendicular to the cable and discuss the best practices to overcome the challenges in analyzing this large data set.
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Zou, Da Peng, and Run Hua Liu. "The First Arrival Cycle Judgment Based Calculated Method for In Situ Acoustic Measurement of Attenuation in Water." Applied Mechanics and Materials 738-739 (March 2015): 877–81. http://dx.doi.org/10.4028/www.scientific.net/amm.738-739.877.
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The propagation loss of water is important in sediment acoustics and underwater acoustics. The propagation loss in water is analyzed theoretically and an in-situ acoustic instrument of Attenuation Array is used to measure attenuation of water. Based on the first arrival cycle (FAC) judgment method, point judgment based data analysis method (PJDAM) and cross correlation based data analysis method (CCDAM) have the similar results of attenuation as 20.89±4.67 dB/m and 22.43±7.37 dB/m respectively in a wide range of measurement frequency changing from 100 to 300 kHz, which is close to the theoretical calculation of 22.64 dB/m in water using the Attenuation Array. The analysis method will be useful in in-situ acoustic measurement of seafloor surficial sediment.
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Stepanov, Robert, Vladimir Pakhov, Andrey Bozhenko, Andrey Batrakov, Lyaysan Garipova, Alexander Kusyumov, Sergey Mikhailov, and George N. Barakos. "Experimental and numerical study of rotor aeroacoustics." International Journal of Aeroacoustics 16, no. 6 (September 2017): 460–75. http://dx.doi.org/10.1177/1475472x17730447.
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The work documents recent experiments at the Kazan National Research Technical University named after A.N. Tupolev (Kazan Aviation Institute), related to helicopter acoustics. The objective is to measure nar-field acoustics of rotors in hover and provide data suitable for computational fluid dynamics validation. The obtained set of data corresponds to a scaled rotor of known planform and the results are of high resolution. An advantage of the current dataset is that direct near-field acoustic data is made available and this allows for easy and direct comparisons with computational fluid dynamics predictions, without the need to use far-field aeroacoustic methods.
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Yang, Sijie. "Challenges and solutions pertinent to machine learning-based audio recognition." Highlights in Science, Engineering and Technology 76 (December 31, 2023): 638–41. http://dx.doi.org/10.54097/n54zq395.
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The problem of transcribing data from an acoustic waveform has yielded multiple approaches over the last decades. The current preferred approach involves a three-stage model that breaks the problem into its constituent stages, each with an equivalent model. The first stage divides pure acoustics and language study using a Bayesian model. The second stage focuses on the acoustics model; this model makes the most sufficient and efficient division. The third stage focuses on the acoustics model; this model provides complete instruction on how to compute the probability required by the first stage, given the division specification declared within the second stage.
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Shin, Sungjin, Geunhwan Kim, YoungSang Hwang, Juho Kim, and Youngmin Choo. "Effective feature fusion via analysis of quantitative similarity matrices among various acoustic features for underwater active target detection." Journal of the Acoustical Society of America 154, no. 4_supplement (October 1, 2023): A340. http://dx.doi.org/10.1121/10.0023731.
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For underwater active target detection, using conventional machine learning technique is limited and unsuitable because of small training data samples and diversity of environment. Therefore, to apply conventional machine learning for underwater acoustics target detection, three methodologies can be manipulated (1) feature, (2) architecture, and (3) learning strategy. In this paper, we implement various acoustic features in terms of feature similarity and feature fusion. From numerous studies in field of acoustics, various acoustic feature extraction methods have been proposed such as Mel-frequency cepstral coefficient, Gammatone-frequency cepstral coefficient, cepstral coefficient, short-time Fourier transform, constant Q transform, and wavelet packet decomposition. In this paper, we calculate a quantitative similarity between acoustic features by interpreting their data distributions with the corresponding probability densities in a reduced dimension. Furthermore, we fuse the acoustic features by simple concatenation. Fusion of a strongly correlated two-dimensional features tends to follow the performance of poor one, whereas the fusion of weakly correlated features improves performance remarkably. The performance improvement by the fusion of weakly correlated features is attributable to complementing acoustic information each other.
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Sert, Fatma Yelkenci, and Özgül Yılmaz Karaman. "An Investigation on the Effects of Architectural Features on Acoustical Environment of Historical Mosques." Acoustics 3, no. 3 (August 7, 2021): 559–80. http://dx.doi.org/10.3390/acoustics3030036.
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In the historical period, different mosques were built in the Anatolian side; the differences in size, typology and style were affected by the climate conditions, cultural and social aspects, availability of materials and the construction techniques of the region they were built in. The ceiling structure, which is the most influencing factor for mosque acoustics, is designed with either curvilinear elements or a flat ceiling for mosques. In the context of our case study, the eight historical mosques in Turkey, with different materials and types of ceiling structures, are investigated in terms of acoustical characteristics in the main prayer hall. Acoustical data are collected by measurements to reveal how the formal differences and material change in ceiling structures affect the acoustic environments of mosques with similar volume. Distribution of acoustical parameters and the suitability of the values obtained through measurements are compared to reflect the effect of architectural features on the acoustical characteristics of the prayer hall.
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Blanford, Thomas E., Luke Garrett, J. Daniel Park, and Daniel C. Brown. "Leveraging audio hardware for underwater acoustics." Journal of the Acoustical Society of America 151, no. 4 (April 2022): A248—A249. http://dx.doi.org/10.1121/10.0011221.
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Both active and passive underwater acoustic systems frequently use purpose built hardware that is designed for a particular application. Transducers, electronics, and data acquisition systems for field experiments, therefore, are often expensive, tailored to limited frequency bands, or packaged for integration with a specific platform. Reliance on custom hardware, however, can make initial experimental investigations of new sensing paradigms cost prohibitive. The expense also creates an entry barrier to experimental work for students and researchers outside the underwater acoustics community. Audio hardware, however, is widely available, easily integrated using commercial data acquisition tools, and is often of relatively low cost. This presentation will describe two efforts to use audio hardware for inexpensive experimental investigations of underwater acoustics topics. The first, AirSAS, uses audio transducers and electronics to investigate synthetic aperture sonar problems in air that are analogous to those underwater. The second, the Citizen Scientist Hydrophone, integrates underwater transducers with consumer audio electronics to make an inexpensive, multipurpose passive sensing device. Challenges and limitations of using commercial audio hardware for underwater acoustics, especially as they relate to accuracy and data quality, will be discussed.
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Acosta, Oscar, Luis Hermida, Marcelo Herrera, Carlos Montenegro, Elvis Gaona, Mateo Bejarano, Kevin Gordillo, Ignacio Pavón, and Cesar Asensio. "Remote Binaural System (RBS) for Noise Acoustic Monitoring." Journal of Sensor and Actuator Networks 12, no. 4 (August 14, 2023): 63. http://dx.doi.org/10.3390/jsan12040063.
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The recent emergence of advanced information technologies such as cloud computing, artificial intelligence, and data science has improved and optimized various processes in acoustics with potential real-world applications. Noise monitoring tasks on large terrains can be captured using an array of sound level meters. However, current monitoring systems only rely on the knowledge of a singular measured value related to the acoustic energy of the captured signal, leaving aside spatial aspects that complement the perception of noise by the human being. This project presents a system that performs binaural measurements according to subjective human perception. The acoustic characterization in an anechoic chamber is presented, as well as acoustic indicators obtained in the field initially for a short period of time. The main contribution of this work is the construction of a binaural prototype that resembles the human head and which transmits and processes acoustical data on the cloud. The above allows noise level monitoring via binaural hearing rather than a singular capturing device. Likewise, it can be highlighted that the system allows for obtaining spatial acoustic indicators based on the interaural cross-correlation function (IACF), as well as detecting the location of the source on the azimuthal plane.
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Rasmuson, Leif K., Stephanie A. Fields, Matthew T. O. Blume, Kelly A. Lawrence, and Polly S. Rankin. "Combined video–hydroacoustic survey of nearshore semi-pelagic rockfish in untrawlable habitats." ICES Journal of Marine Science 79, no. 1 (December 20, 2021): 100–116. http://dx.doi.org/10.1093/icesjms/fsab245.
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Abstract New survey technologies are needed to survey untrawlable habitats in a cost-effective and nonlethal manner with minimal impacts on habitat and nontarget species. Here, we test the efficacy of integrating data from a suspended underwater camera with acoustic data to generate population estimates for nearshore Black (Sebastes melanops), Blue (Sebastes mystinus), and Deacon Rockfish (Sebastes diaconus). We surveyed Seal Rock Reef near Newport, Oregon, and compared our results to population estimates derived from a mark–recapture study conducted at the same reef. We compared fish density estimates from video deployments to those calculated from applying published target strength to length regression models to our acoustics data. Densities derived from the acoustics, using a generalized physoclist target strength to length model, were significantly different from densities derived from video; conversely, a rockfish-specific target strength to length model generated densities that were not statistically different from video densities. To assess whether, and how, fish behaviour was influenced by the presence of an underwater camera, we deployed our camera under the acoustic transducer. No statistical difference was observed in the acoustic density of fish before, during, or after camera deployment. Our work suggests that combining acoustic and stereo video data provided a similar population estimate to historic survey results, but an accurate acoustic density estimate was dependent on using the proper acoustic target–strength model. We contend that combining camera data with hydroacoustic data is effective for surveying rockfish in untrawlable habitats.
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Brandt, Stephen B. "Getting the most out of acoustic data: Linking acoustics with spatially explicit ecological models." Journal of the Acoustical Society of America 98, no. 5 (November 1995): 2880. http://dx.doi.org/10.1121/1.413126.
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Kloepper, Laura N., Meike Linnenschmidt, Zelda Blowers, Brian Branstetter, Joel Ralston, and James A. Simmons. "Estimating colony sizes of emerging bats using acoustic recordings." Royal Society Open Science 3, no. 3 (March 2016): 160022. http://dx.doi.org/10.1098/rsos.160022.
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The decline of bats demands more widespread monitoring of populations for conservation and management. Current censusing methods are either prone to bias or require costly equipment. Here, we report a new method using passive acoustics to determine bat count census from overall acoustic amplitude of the emerging bat stream. We recorded the video and audio of an emerging colony of Mexican free-tailed bats from two cave locations across multiple nights. Instantaneous bat counts were calculated from the video frames, and the bat stream’s acoustic amplitude corresponding to each video frame was determined using three different methods for calculating acoustic intensity. We found a significant link between all three acoustic parameters and bat count, with the highest R 2 of 0.742 linking RMS pressure and bat count. Additionally, the relationship between acoustics and population size at one cave location could accurately predict the population size at another cave location. The data were gathered with low-cost, easy-to-operate equipment, and the data analysis can be easily accomplished using automated scripts or with open-source acoustic software. These results are a potential first step towards creating an acoustic model to estimate bat population at large cave colonies worldwide.
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Kurra, Selma, and Ayca Sentop. "Interaction between annoyance, indoor noise levels and acoustic classification of buildings." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 1 (February 1, 2023): 6519–30. http://dx.doi.org/10.3397/in_2022_0980.
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Assessment of annoyance "at home" from environmental noises has been widely investigated so far and the ISO/TS 15666:2021 was developed to lead the socio-acoustic surveys. On the other hand, the rating of buildings' acoustical performance considering also the indoor noises, has been also well concerned in building acoustics and the studies have ended up with the ISO/TS 19488:2021 covering the acoustic classification system for buildings. Basically the rating system needs to be supported by the subjective tests in the field or in laboratories, to acquire data about the annoyance/disturbance or satisfaction of residents. If the target is to design the healthy, comfortable and sustainable acoustical environment, both technical standards might be harmonized in the future. In this paper, based on the dose/response relationships with respect to the indoor noise levels, an approach is proposed to translate the acoustic classes proposed in ISO/TS 19488, into the annoyance boundaries in terms of different scales (verbal/numerical and the HA% ) referred in ISO/TS 15666. The results from the previous laboratory and field studies conducted by the authors, have been used for verification of this approach.
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Barrett, Natasha. "Interactive Spatial Sonification of Multidimensional Data for Composition and Auditory Display." Computer Music Journal 40, no. 2 (June 2016): 47–69. http://dx.doi.org/10.1162/comj_a_00358.
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This article presents a new approach to interactive spatial sonification of multidimensional data as a tool for spatial sound synthesis, for composing temporal–spatial musical materials, and as an auditory display for scientists to analyze multidimensional data sets in time and space. The approach applies parameter-mapping sonification and is currently implemented in an application called Cheddar, which was programmed in Max/MSP. Cheddar sonifies data in real time, where the user can modify a wide variety of temporal, spatial, and sonic parameters during the listening process, and thus more easily uncover patterns and processes in the data than when applying non-real-time, noninteractive techniques. The design draws on existing literature concerning perception and acoustics, and it applies the author's practical experience in acousmatic composition, spectromorphology, and sound semantics, while addressing accuracy, flexibility, and ease of use. Although previous sonification applications have addressed some degree of real-time control and spatialization, this approach integrates space and sound in an interactive framework. Spatial information is sonified in high-order 3-D ambisonics, where the user can interactively move the virtual listening position to reveal details easily missed from fixed or noninteractive spatial views. Sounds used as input to the sonification take advantage of the rich spectra and extramusical attributes of acoustic sources, which, although previously theorized, are investigated here in a practical context thoroughly tested alongside acoustic and psychoacoustic considerations. Furthermore, when using Cheddar, no specialized knowledge of programming, acoustics, or psychoacoustics is required. These approaches position Cheddar at the junction between science and art. With one application serving both disciplines, the patterns and processes of science are more fluently appropriated into music or sound art, and vice versa for scientific research, science public outreach, and education.
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Mutlu, Erhan. "A Package of Script Codes, POSIBIOM for Vegetation Acoustics: POSIdonia BIOMass." Journal of Marine Science and Engineering 11, no. 9 (September 13, 2023): 1790. http://dx.doi.org/10.3390/jmse11091790.
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Macrophytes and seagrasses play a crucial role in a variety of functions in marine ecosystems and respond in a synchronized manner to a changing climate and the subsequent ecological status. The monitoring of seagrasses is one of the most important issues in the marine environment. One rapidly emerging monitoring technique is the use of acoustics, which has advantages compared to other remote sensing techniques. The acoustic method alone is ambiguous regarding the identities of backscatterers. Therefore, a computer program package was developed to identify and estimate the leaf biometrics (leaf length and biomass) of one of the most common seagrasses, Posidonia oceanica. Some problems in the acoustic data were resolved in order to obtain estimates related to problems with vegetation as well as fisheries and plankton acoustics. One of the problems was the “lost” bottom that occurred during the data collection and postprocessing due to the presence of acoustic noise, reverberation, interferences and intense scatterers, such as fish shoals. Another problem to be eliminated was the occurrence of near-bottom echoes belonging to submerged vegetation, such as seagrasses, followed by spurious echoes during the survey. The last one was the recognition of the seagrass to estimate the leaf length and biomass, the calibration of the sheaths/vertical rhizomes of the seagrass and the establishment of relationships between the acoustic units and biometrics. As a result, an autonomous package of code written in MATLAB was developed to perform all the processes, named “POSIBIOM”, an acronym for POSIdonia BIOMass. This study presents the algorithms, methodology, acoustic–biometric relationship and mapping of biometrics for the first time, and discusses the advantages and disadvantages of the package compared to the software dedicated to the bottom types, habitat and vegetation acoustics. Future studies are recommended to improve the package.
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Mackinson, Steven, Jeroen van der Kooij, and Suzanna Neville. "The fuzzy relationship between trawl and acoustic surveys in the North Sea." ICES Journal of Marine Science 62, no. 8 (January 1, 2005): 1556–75. http://dx.doi.org/10.1016/j.icesjms.2005.06.007.
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Abstract Adding information on the horizontal and vertical distribution of fish both on and between trawl stations is reason enough to perform acoustic surveys routinely in tandem with annual groundfish trawl surveys. Ideally, acoustic and trawl density indices could be combined to maximize information on fish distribution and provide more reliable estimates of stock size. The core of the problem boils down to the question: “how does what we see on an echosounder relate to what we catch in a net?” The fuzzy logic “model-free estimation” approach presented here sidesteps the need to understand specific mechanisms that determine the nature and variability of any relationship between acoustics and trawl catches. Fuzzy logic models that describe and predict the relationship linking acoustics and environmental variables (inputs) with trawl catches (output) are developed, and the sensitivities and robustness of the approach are discussed. In the models examined, the static environmental variables location and depth proved to be better predictors of trawl catches in the North Sea than the acoustic energy in the first 5 m off the bottom. We suggest that finding the “hidden” relationship between acoustics and trawls will require closer attention to partitioning the acoustics data by species/assemblages and understanding the key gear and behavioural differences responsible for producing the high between-gear variability.
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Hambric, Stephen A. "Practical tutorial on cylindrical structure vibro-acoustics Part 2 - Acoustics." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 268, no. 3 (November 30, 2023): 5850–60. http://dx.doi.org/10.3397/in_2023_0841.
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In part 1 of this tutorial (proceedings of Inter-noise 2022) I explained vibrations in cylindrical shell structures. In that paper I limited the mathematics and focused on the key behavior of shells based on critical parameters like the ring frequency, helical wavenumbers, and mean mobilities over different frequency ranges. I compared measured data to the simple theories. In part 2, I focus on the acoustics of cylindrical shells, including sound within shells and the sound radiated outside them. Exterior sound radiation depends strongly on the circumferential order of the shell modes. Breathing modes near the ring frequency radiate sound extremely well, but have very high impedances, so can be difficult to excite. Beam-like modes, where the entire shell cross-section vibrates transversely, radiate less efficiently, but can be easily driven. Higher order, or 'lobar' modes radiate even less efficiently, but nevertheless are commonly observed in radiated sound spectra due to their low impedances. I also review statistical estimates of radiation efficiency of groups of shell modes, which show clear peaks at both the ring frequency as well as at the critical frequency of bending waves. The mathematics of sound inside cylindrical shells is some of the most challenging in vibro-acoustics. At low frequencies, however, the interior sound is dominated by simple one-dimensional planar acoustic waves. At higher frequencies, the sound depends on how well a shell vibration field matches the interior acoustic field based on proximity of resonance frequencies and the similarity of mode shape orders, as well as the 'cut on' frequencies of higher order internal acoustic modes. Finally, I review the well-known phenomenon of how a low shell wall impedance can reduce the effective acoustic sound speed of one-dimensional waves inside cylindrical shells.
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Wang, Guo, Yibin Wang, Yongzhi Min, and Wu Lei. "Blind Source Separation of Transformer Acoustic Signal Based on Sparse Component Analysis." Energies 15, no. 16 (August 19, 2022): 6017. http://dx.doi.org/10.3390/en15166017.
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In the acoustics-based power transformer fault diagnosis, a transformer acoustic signal collected by an acoustic sensor is generally mixed with a large number of interference signals. In order to separate transformer acoustic signals from mixed acoustic signals obtained by a small number of sensors, a blind source separation (BSS) method of transformer acoustic signal based on sparse component analysis (SCA) is proposed in this paper. Firstly, the mixed acoustic signals are transformed from time domain to time–frequency (TF) domain, and single source points (SSPs) in the TF plane are extracted by identifying the phase angle differences of the TF points. Then, the mixing matrix is estimated by clustering SSPs with a density clustering algorithm. Finally, the transformer acoustic signal is separated from the mixed acoustic signals based on the compressed sensing theory. The results of the simulation and experiment show that the proposed method can separate the transformer acoustic signal from the mixed acoustic signals in the case of underdetermination. Compared with the existing denoising methods of the transformer acoustic signal, the denoising results of the proposed method have less error and distortion. It will provide important data support for the acoustics-based power transformer fault diagnosis.
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Jang, Junsu, and Florian Meyer. "Bayesian navigation in shallow water using passive acoustics." Journal of the Acoustical Society of America 153, no. 3_supplement (March 1, 2023): A304. http://dx.doi.org/10.1121/10.0018938.
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Autonomous underwater vehicle (AUV) navigation relying on active acoustic sources causes noise pollution, while dead reckoning leads to a localization error that increases with time. Therefore, AUV navigation based on passive acoustics is appealing. However, for AUV navigation, extracting location information with passive acoustics is a challenging signal processing task. Due to the small form factor of an AUV as a sensing platform, only a single hydrophone or a small aperture hydrophone array can be used as an acoustic sensor. Furthermore, the acoustic signals originate from uncooperative sources. Here, we propose a Bayesian navigation approach for an AUV that exploits acoustic signals generated from sources of opportunity (SOOs) in a shallow water environment. The waveguide invariant (WI) parameter is estimated from cross-correlation coefficients of non-linearly transformed tonal signals of an SOO. It is assumed that the location information of the SOO is transmitted by an automatic identification system. Additionally, the range rate is inferred using the spectrum of cross-correlatedacoustic fields over a time interval. The WI parameter estimate, the range rate estimate, and inertial measurements are fused in a Bayesian parameter estimation approach. The navigation capability is demonstrated using simulated and real data from the SwellEx-96 experiment.
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Woszczyk, Wieslaw, Doyuen Ko, and Brett Leonard. "Virtual Acoustics at the Service of Music Performance and Recording." Archives of Acoustics 37, no. 1 (March 1, 2012): 109–13. http://dx.doi.org/10.2478/v10168-012-0015-6.
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Abstract Virtual or active acoustics refers to the generation of a simulated room response by means of electroacoustics and digital signal processing. An artificial room response may include sound reflections and reverberation as well as other acoustic features mimicking the actual room. They will cause the listener to have an impression of being immersed in virtual acoustics of another simulated room that coexists with the actual physical room. Using low-latency broadband multi-channel convolution and carefully measured room data, optimized transducers for rendering of sound fields, and an intuitive touch control user interface, it is possible to achieve a very high perceived quality of active acoustics, with a straightforward adjustability. The electroacoustically coupled room resulting from such optimization does not merely produce an equivalent of a back-door reverberation chamber, but rather a fully functional complete room superimposed on the physical room, yet with highly selectable and adjustable acoustic response. The utility of such active system for music recording and performance is discussed and supported with examples.
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Fan, Feng, Yaxiong Cao, Lusheng Jiang, and Yongfeng Lin. "Research on Calculation Method for Acoustic Scattering of Helicopter Noise." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, no. 6 (December 2020): 1275–83. http://dx.doi.org/10.1051/jnwpu/20203861275.
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A new calculation method of helicopter rotor/fuselage acoustic scattering is developed. Firstly, a CFD analysis model is developed to simulate flow field of the rotor, which is based on the motional embedded grid system and RANS equations, and provides aerodynamic data for rotor noise calculation. Then, FW-H equations are employed to calculate the aeroacoustic characteristics of isolated rotor, and G 1A formulas are applied to calculate the rotor acoustic gradient to provide boundary condition for acoustic scattering. Based on these, the time-domain equivalent source method is applied to calculate acoustic scatter field, and the total acoustic field that considered the fuselage scatter is superposed by isolated rotor acoustics and the scatter one. Finally, the numerical simulations of helicopter main-rotor/fuselage and tail-rotor/fuselage scatter effect are conducted by using the developed models. The results indicate that the helicopter fuselage has important scatter effect on the high frequency acoustics of main rotor and tail rotor, and the acoustic scatter effect become more obvious with the smaller space between the main rotor (tail rotor) and fuselage.
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Gable, Todd J. "Speaker verification system using acoustic data and non-acoustic data." Journal of the Acoustical Society of America 125, no. 5 (2009): 3487. http://dx.doi.org/10.1121/1.3139583.
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Gable, Todd J. "Speaker verification system using acoustic data and non-acoustic data." Journal of the Acoustical Society of America 120, no. 4 (2006): 1770. http://dx.doi.org/10.1121/1.2372387.
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Astolfi, Arianna, Greta Minelli, and Giuseppina Emma Puglisi. "A basic protocol for the acoustic characterization of small and medium-sized classrooms." Journal of the Acoustical Society of America 152, no. 3 (September 2022): 1646–59. http://dx.doi.org/10.1121/10.0013504.
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To promote a fast and effective characterization of the sound environment in small and medium-sized classrooms, a basic measurement protocol, based on a minimum number of parameters and positions, is provided. Measurements were taken in 29 occupied classrooms belonging to 13 primary schools in Turin, Italy, that differ in location and typology. The background noise level was acquired during silent and group activities, and the reverberation time, speech clarity, useful-to-detrimental ratio and speech level, were acquired along the main axis of each classroom and in one or two offset positions. To reduce the number of measured parameters that can be used to fully characterize classroom acoustics, data were divided into two groups on the basis of a cutoff value of maximum occupied reverberation time in the case of moderate and severe requirements. Given the strong correlation among the quantities, thresholds were identified for the other acoustical parameters, and their accuracy and precision were tested to assess their ability to classify the acoustic quality as compliant or non-compliant. Results suggest that more convenient parameters, like clarity in the central position of the classroom, can be used instead of reverberation time to classify classroom acoustics.
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Stiles, Timothy A., Ronald E. Kumon, and Daniel Ludwigsen. "Impact of industrial partnerships in the acoustics program at Kettering University." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A253. http://dx.doi.org/10.1121/10.0016185.
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Kettering University has an experiential learning model in which students typically alternate between academic and cooperative work terms every quarter during their entire undergraduate degree program. In this approach, industrial partners play a particularly critical role. In this talk, we will discuss how partnerships with industry have impacted our classroom experiences and inspired curricular elements that incorporate theoretical, computational, and experimental approaches to solve problems in acoustics. We will highlight some of the work related to acoustics that students have done in their co-op projects and how students have served as a bridge between the academic and corporate environments. The course “Acoustics in the Human Environment” has recently benefited from a grant from the Head Acoustics Foundation. The course was revamped in Spring 2022 to include more detailed analysis and a jury study that make use of this donation. The course “Acoustic Testing and Modeling” uses Siemens Simcenter Testlab to acquire experimental data and Comsol for computer simulations. Recently, this course has added a module on Laser Doppler Vibrometry that makes use of equipment from Polytec. The efforts in these courses have enabled students to be better prepared for acoustic testing projects for a thesis or co-operative employment terms.
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Putra, Alnugraha Rachman, and Ryanty Derwentyana Nazhar. "Peranan Material Interior dalam Pengendalian Akustik Auditorium Bandung Creative Hub." Waca Cipta Ruang 6, no. 2 (November 27, 2020): 71–76. http://dx.doi.org/10.34010/wcr.v6i2.4123.
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Acoustics in an auditorium interior have a vital role in the continuity of activities in it. Activities in the auditorium are closely related to audio and visual, so designing an auditorium requires an acoustic control system, not only visual elements are considered, but also sound or acoustic control requires special attention. This study describes the role of interior materials in acoustic control in a multifunctional auditorium in the Bandung Creative Hub building, West Java. To determine the quality of the room acoustics under study, the research method used is descriptive analysis by processing data in the form of images, field notes, documentation, and supporting theories according to the principles of interior design science. This study concludes that the interior materials in the multifunctional auditorium in the Bandung Creative Hub Building have met the applicable standards in the acoustic control of the auditorium space. The benefit of this research is that it can be used as a benchmark for auditorium design and can be a reference for space design that requires special acoustic treatment in the future.