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Newbold, Carrie. "Electrode tissue interface : development and findings of an in vitro model /." Connect to thesis, 2006. http://repository.unimelb.edu.au/10187/1692.
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In the period immediately following the implantation of a cochlear implant electrode array within the cochlear environment, the power required to stimulate the auditory nerve at preset current levels increases. This rise is due to increases in electrode impedance which in turn is suggested to be a result of tissue growth around the electrode array. The foreign body response initiated by the immune system encapsulates the array in a matrix of fibrous tissue, separating the electrode array from the rest of the body. A second change in electrode impedance occurs with the onset of electrical stimulation. A transitory reduction in impedance has been recorded in animals and humans after stimulation of electrodes. Impedance returns to pre-stimulation levels following the cessation of stimulation. It was suggested that these changes in impedance with stimulation were also related to the tissue growth around the electrode array. A more thorough understanding of the interface was required to ascertain these concepts.
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Wolmarans, Hendrik Petrus. "Cochlear implant speech processing, based on the cochlear travelling wave." Diss., Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-01242006-112642.
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Oosthuizen, Ilze. "Bilateral processing benefit in sequentially implanted adult cochlear implant users." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/30304.
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Bilateral cochlear implantation is accepted medical practice since 2008 in clinically suitable adults and children to enhance bilateral processing benefits. Bilateral implantation may lead to the restoration of some bilateral hearing advantages, such as improved speech recognition in noise, localisation, head shadow effect, summation, and squelch. The majority of the advantages stated in literature, though, are characteristic of the simultaneously implanted cochlear implant population. Simultaneous implantation is not yet a reality in South Africa due to funding constraints, therefore determining the bilateral processing abilities in sequentially implanted adults is essential. Determining bilateral processing benefits achievable with sequential implantation could result in evidence-based recommendations in terms of candidacy considerations, surgery protocols, motivations for medical aid funding for simultaneous cochlear implantation, and relevant measures to determine the bilateral processing benefit attainable. Furthermore, it might enhance audiologists‟ insight regarding post-implantation performance of sequentially implanted patients and enable them to counsel prospective candidates realistically. The aaim of this study was to determine the bilateral benefit attained by sequentially implanted adults. A quantitative, cross-sectional research approach was followed in a one group post-test-only exploratory research design. A purposive convenient sampling method with specified selection criteria was used to select 11 adult clients of an established cochlear implant programme in Pretoria. Tests of sound localisation in the horizontal plane and speech perception in noise were performed. During the test of sound localisation, performance with only the first or only the second implant was found to be very similar. For the majority of participants the second cochlear implant (CI 2) was the superior performing implant during xviii speech perception in noise testing, in spatially separated speech and noise conditions where noise was directed to the first implant, as well as in spatially coincident speech and noise. A statistical significant bilateral benefit (p < 0.05) was attained by sequentially implanted adults for sound localisation. A bilateral benefit for speech perception in noise was observed when noise was directed to the first implant and in the diotic listening condition with average benefits of 1.69 dB and 0.78 dB, respectively. It was not statistically significant (p > 0.05), however, and was smaller than bilateral benefit values achieved by simultaneously implanted adults in previous studies. The head shadow effect at 180° was found to be the strongest and most robust bilateral spatial benefit. Squelch and summation benefit values ranged from negative values to 2 dB and 6 dB, respectively. This corresponded with values found in previous studies. The improvement in speech perception in spatially distinct speech and noise from adding the ear with a better SNR (signal to noise ratio) indicated that the contribution of CI 2 seems to be greater than that of CI 1 for bilateral spatial benefit. It can be concluded that adults with sequential implants may achieve some extent of bilateral benefit even with many years of unilateral implant use, when speech processors differ, when the second implant is done ≥ 10 years after the first implant, and in cases of prelingual deafness. A key benefit of sequential implantation appears to be related to the advantage of having hearing on both sides so that the ear with the more favourable environmental signalto-noise ratio is always available. AFRIKAANS : Bilaterale kogleêre inplanting is sedert 2008 aanvaarde mediese praktyk vir klinies geskikte volwassenes en kinders, ten einde bilaterale prosesseringsvoordeel te verhoog. Bilaterale inplanting kan lei tot die herstel van sommige van die voordele van bilaterale gehoor, soos verbeterde spraakherkenning in lawaai, klanklokalisering, die kopskadueffek, sommering en selektiewe onderdrukking (“squelch”). Die meeste van die voordele wat in die literatuur bespreek word, is egter kenmerkend van dié persone by wie twee kogleêre inplantings gelyktydig gedoen is. Gelyktydige inplanting is as gevolg van beperkte befondsing nog nie in Suid-Afrika 'n werklikheid nie, daarom is dit noodsaaklik om te bepaal watter bilaterale prosesseringsvoordele by opeenvolgend-geïnplanteerde volwassenes voorkom. Die bepaling van watter bilaterale prosesseringsvoordele met opeenvolgende inplanting bereik kan word, sou kon lei tot getuienis-gebaseerde aanbevelings met betrekking tot besluite oor die geskiktheid van kandidate, protokol vir sjirurgie, motiverings vir die befondsing van gelyktydige kogleêre inplantings deur mediese voorsorgfondse, en toepaslike maatstawwe om te bepaal watter mate van bilaterale prosesseringsvoordeel haalbaar sou wees. Dit sou verder oudioloë se insig kon verbreed met betrekking tot die na-operatiewe prestasie van opeenvolgend-geïnplanteerde persone en hulle sodoende in staat stel om voornemende kandidate van realistiese raad te bedien. Die doel van hierdie studie was om te bepaal wat die bilaterale prosesseringsvoordele is wat deur opeenvolgend-geïnplanteerde volwassenes verkry kan word. 'n Kwantitatiewe navorsingsbenadering met 'n dwarsprofiel van „n enkelgroep is gevolg, met 'n post-toets verkennende navorsingsontwerp. 'n Doelgerigte gerieflikheidssteekproef met 'n gespesifiseerde seleksiekriteria is gebruik om 11 volwasse kliënte van 'n gevestigde kogleêre inplantprogram in Pretoria te selekteer. Klanklokalisering in die horisontale vlak en die waarneming van spraak in lawaai is getoets. Tydens die toets vir klanklokalisering is gevind dat prestasie met slegs die eerste of slegs die tweede inplanting soortgelyk was. Vir die meeste deelnemers aan die studie het die tweede kogleêre inplanting (KI 2) die beste prestasie gelewer tydens spraakwaarneming in lawaai, in omstandighede waar spraak en lawaai ruimtelik geskei is en die lawaai op die eerste inplanting gerig is, asook in omstandighede waar spraak en lawaai ruimtelik saamvoorkomend aangebied is. 'n Statisties beduidende bilaterale voordeel (p < 0.05) is deur opeenvolgend-geïnplanteerde volwassenes vir klanklokalisering behaal. 'n Bilaterale voordeel vir spraakwaarneming in lawaai is waargeneem waar lawaai op die eerste inplanting gerig is en ook in diotiese luistertoestande, met 'n gemiddelde voordeel van 1.69 dB en 0.78 dB, onderskeidelik. Dit was egter nie statisties beduidend nie en was ook kleiner as die bilaterale voordeelwaardes wat in vorige studies deur gelyktydig-geïnplanteerde volwassenes behaal is. Die kopskadu-effek by 180° was die sterkste en mees robuuste bilaterale ruimtelike voordeel. Voordeelwaardes vir selektiewe onderdrukking en sommering het gewissel van negatiewe waardes tot 2 dB en 6 dB onderskeidelik. Dit stem ooreen met waardes wat in vorige studies gevind is. Die verbetering in spraakwaarneming in ruimtelik geskeide spraak en lawaai wat verkry is deur die oor met 'n beter STR (sein-tot-ruis ratio) by te voeg, het daarop gedui dat die bydrae van KI 2 tot bilaterale ruimtelike voordeel waarskynlik groter as die bydrae van KI 1 is. Die gevolgtrekking kan gemaak word dat volwassenes met opeenvolgende inplantings 'n mate van bilaterale voordeel verkry selfs na vele jare van unilaterale inplantingsgebruik, wanneer die spraakprosesseerders in die twee inplantings van mekaar verskil, wanneer die tweede inplanting ≥ 10 jaar na die eerste plaasvind, en in gevalle van prelinguale doofheid. 'n Sleutelvoordeel van opeenvolgende inplanting hou klaarblyklik verband met die voordeel van gehoor aan albei kante te hê sodat die oor met die gunstigste sein-tot-lawaai ratio altyd beskikbaar is.<br>Dissertation (MCommunication Pathology)--University of Pretoria, 2012.<br>Speech-Language Pathology and Audiology<br>Unrestricted
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Looi, V. "Music Perception of Cochlear Implant Users." Thesis, University of Canterbury. Department of Communication Disorders, 2006. http://hdl.handle.net/10092/2200.
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Graser, Peter. "Sprachentwicklungsstörungen bei Kindern mit Cochlear Implant." Heidelberg Winter, 2005. http://deposit.d-nb.de/cgi-bin/dokserv?id=2935522&prov=M&dok_var=1&dok_ext=htm.
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Graser, Peter. "Sprachentwicklungsstörungen bei Kindern mit Cochlear Implant /." Heidelberg : Winter, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=2935522&prov=M&dok_var=1&dok_ext=htm.
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Baker, Michael W. (Michael Warren) 1977. "A low-power cochlear implant system." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40494.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.<br>Includes bibliographical references (p. 171-179).<br>Cochlear implants, or bionic ears, restore hearing to the profoundly deaf by bypassing missing inner-ear hair cells in the cochlea and electrically stimulating the auditory nerve. For miniaturized cochlear implants, including behind-the-ear (BTE) models, power consumption is the chief factor in determining cost and patient convenience. This thesis reports on the design of a low-power bionic ear system by addressing three critical signal and power processing subsystems in low-cost CMOS ICs. First, the design of a low-power current-mode front-end for subminiature microphones demonstrates 78dB dynamic range performance with attention to RF noise and supply immunity. Second, hearing-impaired patients need strategies that decide intelligently between listening conditions in speech or noise. This work describes an automatic gain control (AGC) design which uses programmable hybrid analog-digital current-mode feedback to implement a dual-loop strategy, a well-known algorithm for speech in noisy environments. The AGC exhibits level-invariant. stability, programmable time constants and consumes less than 36pW. Third, a feedback-loop technique is explored for analyzing and designing RF power links for transcutaneous bionic ear systems.<br>(cont.) Using feedback tools to minimize algebraic manipulations, this work demonstrates conditions for optimal voltage and power transfer functions. This theory is applied to a bionic implant system designed for load power consumptions in the 1mW - 10mW range, a low-power regime not significantly explored in prior designs. Link efficiencies of 74% and 54% at 1-mm and 10-mm coil separations, respectively, are measured, in good agreement with theoretical predictions. A full cochlear implant system with signal and power processing is explored incorporating the front-end, AGC, and RF power link, as well as analog signal processing channels. This design uses channel data to feedforward program the just-needed electrode power level. My implant system consumes 3mW of power for all audio processing and a stimulation power of 1mW. A fixed-power version of this system dissipates 2.2mW for 1mW of internal stimulation power. As many commercial systems with similar specifications consume 40mW - 80mW, this effort promises a significant reduction in cochlear implant power consumption and cost.<br>by Michael W. Baker.<br>Ph.D.
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Cooper, Huw R. "Auditory grouping in cochlear implant listeners." Thesis, Aston University, 2008. http://publications.aston.ac.uk/12317/.
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This thesis describes a series of experiments investigating both sequential and concurrent auditory grouping in implant listeners. Some grouping cues used by normal-hearing listeners should also be available to implant listeners, while others (e.g. fundamental frequency) are unlikely to be useful. As poor spectral resolution may also limit implant listeners’ performance, the spread of excitation in the cochlea was assessed using Neural Response Telemetry (NRT) and the results were related to those of the perceptual tasks. Experiment 1 evaluated sequential segregation of alternating tone sequences; no effect of rate or evidence of perceptual ambiguity was found, suggesting that automatic stream segregation had not occurred. Experiment 2 was an electrode pitch-ranking task; some relationship was found between pitch-ranking judgements (especially confidence scores) and reported segregation. Experiment 3 used a temporal discrimination task; this also failed to provide evidence of automatic stream segregation, because no interaction was found between the effects of sequence length and electrode separation. Experiment 4 explored schema-based grouping using interleaved melody discrimination; listeners were not able to segregate targets and distractors based on pitch differences, unless accompanied by substantial level differences. Experiment 5 evaluated concurrent segregation in a task requiring the detection of level changes in individual components of a complex tone. Generally, large changes were needed and abrupt changes were no easier to detect than gradual ones. In experiment 6, NRT testing confirmed substantially overlapping simulation by intracochlear electrodes. Overall, little or no evidence of auditory grouping by implant listeners was found.
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Labuschagne, Ilse Bernadette. "Timbre perception of cochlear implant users." Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/31130.
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The timbre perception of cochlear implantees (CI) is poor compared to normal hearing
(NH) listeners. The cues that are normally transmitted to NH listeners may be less salient
or even absent for CI users. From the literature, two spectral (brightness (Tb) and
irregularity (IRR)) and two temporal timbre parameters (log rise-time (LRT) and
sustain/decay (S/D) parameter (n)) have been identified as important timbre parameters.
Each of these parameters was extracted for a set of thirteen instruments. Sounds could be
resynthesized according to the specific timbre parameter set. The variation of loudness,
pitch and perceived duration as functions of the timbre parameters were investigated to
provide systematic balancing methods.
The just-noticeable differences (JNDs) were obtained for each of the parameters for
thirteen instruments for NH listeners and a reduced instrument set of nine instruments for
the CI users using a 1-up, 2-down, two-alternative, forced choice procedure. From the
JNDs, predicted confusion matrices were constructed. From the confusion matrices, a
feature information transmission analysis (FITA) indicated the salience of each of the
parameters and NH and CI results could be compared.<br>Dissertation (MEng)--University of Pretoria, 2011.<br>Electrical, Electronic and Computer Engineering<br>MEng<br>Unrestricted
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Tucker, Eliza M. "Tinnitus in cochlear implantees : cognitive behavioural therapy for cochlear implant users." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/359783/.
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Background to the study: Cochlear implants (CI) can help to suppress tinnitus and often make existing tinnitus more bearable. However, a number of patients still suffer from tinnitus afterwards. In some cases the implantation makes existing tinnitus worse, or tinnitus may occur as a result of cochlear implantation. Because of the inconclusive aetiology of tinnitus it is difficult to treat its effects. So far, one of the most popular treatments for tinnitus is the widely used Cognitive Behavioural Therapy (CBT), which aims to influence dysfunctional emotions, behaviours and cognitions though a goal-orientated, systematic procedure. CBT aims to minimize the side-effects of tinnitus and help to manage it in a more efficient way. CBT has been investigated in several studies and shows promising results in reducing the debilitating effect of tinnitus. CBT has not yet been used specifically for, or investigated in, relation to treating CI users suffering from tinnitus. Aims and outline of the study: Our research aimed to investigate CBT’s effectiveness for cochlear implant users. Using a randomized control trial, we investigated whether two-hour Tinnitus Workshops for the control group were as equally as effective as CBT for the research group. We also explored if either type of treatment for cochlear implant users needed any modifications to make them more suitable for this group of tinnitus sufferers. Using Open Questions, we investigated tinnitus in cochlear implant users. We analysed the Open Questions from both groups, creating a profile of a typical cochlear implant user who suffers from tinnitus, and we also explored whether both interventions (Tinnitus Workshop or CBT) were suitable for this kind of patient. Data was gathered, pre- and post-interventions, by questionnaires; these were Tinnitus Questionnaires (TQ), Visual Analogue Scale (VAS), Quality of Life Short Form 36 Health Survey (SF-36) and Hospital Anxiety and Depression Scale (HADS). Results: In the control group, we found no significant differences between the TQ scores pre- and post-intervention. VAS scores post-intervention were lower than pre-intervention, indicating some improvement in individual tinnitus perception; however, the difference was not significant. In the research group, we found small, but not significant, differences in both TQ pre- and post-intervention (z =1.83, p>.05) and in VAS (z=0.14, p>.05). No significant differences were found between the control and the research group pre- and post-intervention. Conclusions: The questionnaires used in this study, such as TQ or VAS, showed a decrease in general tinnitus distress, but a larger-sized sample group may be needed for greater statistical certainty. The results from the Open Questions showed that cochlear implant users were affected by tinnitus in a similar way to non-cochlear implant users. Overall, both interventions need further, small modifications and adjustments to their protocols in order to be more effective for this type of tinnitus sufferer.
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Arnephy, Janna Maree. "Environmental Sound Perception for Cochlear Implant Users." Thesis, University of Canterbury. Communication Disorders, 2008. http://hdl.handle.net/10092/1848.
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This study compared adult cochlear implant (CI) users to normally hearing (NH) listeners in their ability to identify various environmental sounds. It also assessed the impact of cochlear implantation on speech perception as well as the ability to identify environmental sounds. A comprehensive Environmental Sounds Perception Test (EST) was developed for this study. It was hypothesised that: (i) the NH participants would score higher than the experienced CI users on the EST; (ii) for the pre-to-post CI group, scores on the EST would be higher post-surgery than presurgery, and (iii) for the pre-to-post CI surgery group, scores on speech perception tests would be higher post-surgery than pre-surgery. 10 experienced adult Nucleus CI users and 24 similarly-aged NH subjects were compared on the EST. The study also tested four adults pre-surgery (with HAs), and subsequently post-surgery with the CI on speech perception tests as well as the EST. The closed-set EST consisted of 45 different sounds selected to be representative of everyday stimuli, classified into 9 groups; transport, nature, arriving home, bathroom, kitchen, household appliances, human, office and other. Each sound was represented by two different tokens, ranging in lengths from 2.5 to 12.5 seconds. The results showed that NH participants scored significantly higher than the experienced CI users on the EST (p < 0.001). For the participants tested pre- and post- surgery, the higher scores with the CI than with HAs was approaching significance (p = 0.068) for both the EST and the speech perception measures. No significant correlations were found between scores on the EST and a range of participant factors such as age or speech perception scores for any group. Overall these results suggest that CI users are poorer than NH participants, but better than HA users with severeto- profound hearing losses, in recognizing environmental sounds.
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Panchyk, Halen. "Auditory perceived continuity in cochlear implant listeners." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43420.
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Cochlear implants are generally considered the most successful of all sensory neural prostheses currently in use (Wilson and Dorman, 2008). Investigation of auditory perception with cochlear implants is important for developing effective and evidence-based approaches for intervention and management of profound hearing loss. Various phenomena of auditory perception have begun to be explored with cochlear implant users. However, perception of a phenomenon that allows listeners to perceptually restore the continuity of sounds that are partially masked or interrupted by other sounds (“auditory induction” or “auditory continuity”) has not yet been investigated in a group of listeners with cochlear implants.
In the current study a group of 10 listeners with cochlear implants and 10 control listeners with normal-hearing provided judgments on the continuity of a pure tone signal in the presence of four levels of a narrow-band noise masker. The group of listeners with cochlear implants reported perception of auditory continuity, but did so for lower levels of the masker when compared to the normal-hearing control group. A secondary experiment investigated simultaneous masking in listeners with cochlear implants using the same masker levels used in the continuity experiment. The cochlear implant group displayed effective masking at a lower level than the normal-hearing control group, the same level at which auditory continuity was perceived in the first experiment. The differences observed between the two groups may be attributable to the greater effects of masking resulting from poorer frequency resolution, lack of temporal fine structure information and reduced dynamic range for users of cochlear implants compared with listeners with normal-hearing.
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Whiten, Darren M. (Darren Mark) 1977. "Electro-anatomical models of the cochlear implant." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/38518.
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Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2007.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Includes bibliographical references (p. 211-225).<br>While cochlear implantation has become the standard care in treating patients with severe to profound sensorineural hearing loss, the variation in benefit (communicative ability) individual patients derive from implantation remains both large and, for the most part, unexplained. One explanation for this variation is the status of the implanted ear which, when examined histopathologically, also displays substantial variation due to both the pathogenesis of hearing loss (etiology, etc.) and pathological changes initiated by implantation. For instance, across-patient variation in electrode position and insertion depth is clearly present, as are differential amounts of residual spiral ganglion survival, fibrous tissue formation and electrode encapsulation, cochlear ossification, and idiosyncratic damage to adjacent cochlear structures. Because of the complex geometric electrical properties of the tissues found in the implanted ear, demonstrating the impact of pathological variability on neuronal excitation, and ultimately on behavioral performance, will likely require a detailed representation of the peripheral anatomy. Our approach has been to develop detailed, three-dimensional (3D) electro-anatomical models (EAMs) of the implanted ear capable of representing the aforementioned patient-specific types of pathological variation. In response to electric stimulation, these computational models predict an estimate of (1) the 3D electric field, (2) the cochleotopic pattern of neural activation, and (3) the electrically-evoked compound action potential (ECAP) recorded from intracochlear electrodes. This thesis focuses on three aims. First, two patient-specific EAMs are formulated from hundreds of digital images of the histologically-sectioned temporal bones of two patients, attempting to incorporate the detailed pathology of each. Second, model predictions are compared to relevant reports from the literature, data collected from a cohort of implanted research subjects, and, most importantly, to archival data collected during life from the same two patients used to derive our psychophysical threshold measures, and ECAP recordings) collectively show a promising correspondence between model-predicted and empirically-measured data. Third, by making incremental adjustments to the anatomical representation in the model, the impact of individual attributes are investigated, mechanisms that may degrade benefit suggested, and potential interventions explored.<br>by Darren M. Whiten.<br>Ph.D.
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Saba, R. "Cochlear implant modelling : stimulation and power consumption." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/348818/.
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Cochlear implants have been shown to successfully restore hearing to the profoundly deaf. Despite this achievement, issues remain concerning the power consumption and the accuracy of stimulation. This thesis is mainly concerned with investigating the spread of stimulation voltage within the cochlea. The power required to generate the stimulus is also investigated, as is the feasibility of powering a fully implanted cochlear implant by harvesting energy from head motion. Several different models have been used to study the voltage distribution within the cochlea due to electrical stimulation from individual electrodes of a cochlear implant. A resistive cable model is first used to illustrate the fall-off of the voltage with distance at the electrode positions along the cochlea. A three-dimensional finite element model of the cochlea is then developed to obtain the voltage distribution at positions closer to the site of neural stimulation. This model is used to demonstrate the way that the voltage distribution varies with the geometry of the cochlea and the electrode array. It was found that placing the return electrode of the implant within the modiolus, as opposed to outside the cochlea, resulted in higher stimulation for the same current input, which reduces the power requirements. The model has also been used to investigate the consequences of a current-steering, or stimulation focussing, strategy that has previously been proposed. A generalisation of this strategy is suggested, whereby impedance information at the neural level, along the path of the spiral ganglion, was used to optimise the focussed voltage distribution at the target neurons. The power consumption of various stimulation strategies is then estimated in order to assess their energy efficiency. Strategies are defined by parameters such as stimulation rate and number of active channels. The feasibility has also been investigated of harvesting electrical energy from head motion, to power a fully-implanted cochlear implant. It was demonstrated that more power could be harvested from higher harmonics but that this would be sensitive to walking speed. The practical approach is to have a heavily damped device that is insensitive.
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Withey, Daniel J. (Daniel James) Carleton University Dissertation Engineering Electrical. "A cochlear implant stimulation strategy and system." Ottawa, 1992.
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Taft, Daniel Adam. "Cochlear implant sound coding with across-frequency delays." Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/5783.
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The experiments described in this thesis investigate the temporal relationship between frequency bands in a cochlear implant sound processor. Initial studies were of cochlea-based traveling wave delays for cochlear implant sound processing strategies. These were later broadened into studies of an ensemble of across-frequency delays.<br>Before incorporating cochlear delays into a cochlear implant processor, a set of suitable delays was determined with a psychoacoustic calibration to pitch perception, since normal cochlear delays are a function of frequency. The first experiment assessed the perception of pitch evoked by electrical stimuli from cochlear implant electrodes. Six cochlear implant users with acoustic hearing in their non-implanted ears were recruited for this, since they were able to compare electric stimuli to acoustic tones. Traveling wave delays were then computed for each subject using the frequencies matched to their electrodes. These were similar across subjects, ranging over 0-6 milliseconds along the electrode array.<br>The next experiment applied the calibrated delays to the ACE strategy filter outputs before maxima selection. The effects upon speech perception in noise were assessed with cochlear implant users, and a small but significant improvement was observed. A subsequent sensitivity analysis indicated that accurate calibration of the delays might not be necessary after all; instead, a range of across-frequency delays might be similarly beneficial.<br>A computational investigation was performed next, where a corpus of recorded speech was passed through the ACE cochlear implant sound processing strategy in order to determine how across-frequency delays altered the patterns of stimulation. A range of delay vectors were used in combination with a number of processing parameter sets and noise levels. The results showed that additional stimuli from broadband sounds (such as the glottal pulses of vowels) are selected when frequency bands are desynchronized with across-frequency delays. Background noise contains fewer dominant impulses than a single talker and so is not enhanced in this way.<br>In the following experiment, speech perception with an ensemble of across-frequency delays was assessed with eight cochlear implant users. Reverse cochlear delays (high frequency delays) were equivalent to conventional cochlear delays. Benefit was diminished for larger delays. Speech recognition scores were at baseline with random delay assignments. An information transmission analysis of speech in quiet indicated that the discrimination of voiced cues was most improved with across-frequency delays. For some subjects, this was seen as improved vowel discrimination based on formant locations and improved transmission of the place of articulation of consonants.<br>A final study indicated that benefits to speech perception with across-frequency delays are diminished when the number of maxima selected per frame is increased above 8-out-of-22 frequency bands.
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Lim, Debbie K. Psychology Faculty of Science UNSW. "Cognitive style and adjustment in cochlear implant users." Awarded by:University of New South Wales. School of Psychology, 2005. http://handle.unsw.edu.au/1959.4/21897.
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This program of research investigated the role of cognitive factors in adjustment to cochlear implantation. A cochlear implant is a medical device for severe to profoundly deaf individuals that simulates sound in the cochlea by electrically stimulating the hearing nerve. The audiological benefits of implantation have shown to be highly variable and difficult to predict. This has led to the utilisation of psychological factors to predict adjustment. The aim of this thesis was to develop an understanding of the psychological factors influencing adjustment to implantation within a cognitive framework. Three studies were conducted that investigated the central hypothesis that individuals with a maladaptive cognitive style are more likely to experience poorer psychological adjustment following implantation. Study 1 was a cross-sectional survey that aimed to identify the main predictors of post-implant adjustment in a large representative sample of adult cochlear implant recipients. Participants completed measures of hearing-related cognitions, anxious and depressive symptomatology, emotional reaction to the implant, and hearing-related demographic characteristics. Psychological adjustment was assessed as stress and coping in relation to hearing impairment. The tendency to engage more frequently in negative hearing-related cognitions was found to be the strongest predictor of adjustment. This finding was consistent with the hypothesis that a maladaptive cognitive style plays a key role in determining psychological outcomes following implantation. Study 2 extended Study 1 by experimentally investigating the impact of a specific maladaptive cognitive process, rumination, on cochlear implant recipients' response to an auditory task. Based on the Study 1 finding that negative cognitions predicted poorer adjustment, participants engaged in either a positive or negative rumination task. During rumination, participants focussed on a series of either positive or negative self-statements. Following rumination, participants completed an auditory (story listening) task. Participants then rated their mood, extent of negative cognitions, and the perceived difficulty of the auditory task. Inconsistent with predictions, participants who engaged in negative rumination did not respond more negatively on any of the ratings than participants who engaged in positive rumination. A correlational analysis, however, showed that greater perceived task difficulty was associated with lower frequency of engagement in positive cognitions about hearing. Study 3 employed a thought suppression paradigm to investigate in cochlear implant recipients the effects of suppressing thoughts about hearing difficulty during an auditory task. It was predicted that participants instructed to suppress would experience an increased frequency of target thoughts and greater negative mood, both during and after suppression. During the first (baseline) experimental period, both suppression and non-suppression participants monitored their thoughts by pressing a button when they experienced a thought about hearing difficulty. In the second (suppression) period, suppression participants suppressed their thoughts about hearing difficulty. In the third (post-suppression) period, suppression participants were instructed to no longer suppress their thoughts. Participants who suppressed had an increased frequency of target thoughts subsequent to, but not during, suppression. There were no differences between suppression and non-suppression participants for mood, either during or after suppression. The finding of a delayed increase in target thoughts indicated that attempting to suppress thoughts about hearing difficulty may be a maladaptive cognitive strategy for managing unwanted negative cognitions about hearing in cochlear implant recipients. In concluding, the thesis proposes a cognitive model of adjustment to cochlear implantation that synthesises the findings of the studies conducted and takes into account the cognitive theories that informed the program of research. The major components of this model include the tendency to engage in negative hearing-related cognitions, the maladaptive cognitive processes employed to manage negative hearing-related cognitions, and cognitive load factors. While far from conclusive, the model presents an initial framework within which the current findings can be understood and further hypotheses generated. Methodologically, the model also provides an empirically informed framework for future investigations into the cognitive factors associated with adjustment in cochlear implant users.
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Allen, Karen. "Telephone use and performance in cochlear implant candidates." Thesis, University of Canterbury. Communication Disorders, 2007. http://hdl.handle.net/10092/1458.
Full textAbstract:
Telephones are an integral part of everyday life in today's society. It is well known that hearing impaired people have difficulty understanding speech on the telephone. The ability to use the telephone is commonly reported as one of the many benefits of cochlear implantation. Assessment for a cochlear implant (CI) includes a variety of aspects related to communication and hearing ability. Included in the case history, mention is made whether the person can use the telephone. The purpose of the present study was firstly to identify if the inability to use the telephone could be used a predictor for suitability for a cochlear implant. It was also purposed to determine if telephone ability could be assessed by self-reported measures. The participants were 13 severe to profoundly hearing impaired people who had previously undergone candidacy assessment for a cochlear implant. Each participant was evaluated on their use and understanding of speech on the telephone. Participants were separated into two groups: those who were candidates for a cochlear implant and those who were not. Speech perception testing was evaluated using a recording of CUNY sentences on the telephone. Results indicated that cochlear implant candidates correctly perceived a significantly lower number of words on the telephone than non-candidates. Use of the telephone was evaluated using a 51-item questionnaire. Results indicated that there was no significant difference in self-reported use of the telephone between cochlear implant candidates and non-candidates. The differences in speech perception understanding on the telephone were most likely due to the overall better hearing levels of the non-candidates. The clinical implications of the present study are considered.
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Friesen, Lendra M. "Speech-evoked auditory potentials in cochlear implant listeners /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8239.
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Timm, Lydia [Verfasser]. "Music Perception of Cochlear Implant Users / Lydia Timm." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2013. http://d-nb.info/1030453837/34.
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Kerr, Gillian Robyn. "Long-term cost implications for cochlear implant recipients." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17952.
Full textAbstract:
Thesis (MAud)--University of Stellenbosch, 2011.<br>ENGLISH ABSTRACT: Cochlear implantation is an expensive but cost-effective intervention which must be used for
life. It can provide individuals with severe-to-profound hearing loss improved sound
perception in comparison to that obtained using hearing aids. In South Africa implants are not
state subsidised, and related costs need to be covered by implant recipients. Cochlear
implant teams thus need to ensure that individuals, who are selected, will benefit from the
device and will be able to use it for their lifetime. Implantees should know the immediate and
potential future costs involved, to be able to decide on its affordability.
The primary aim of this study was to determine the immediate and long-term costs of cochlear
implantation. One hundred and fifty four implant recipients from the Tygerberg Hospital-
University of Stellenbosch Cochlear Implant Unit in Cape Town, South Africa were surveyed.
Costs were categorized according to the time period post implantation and were converted to
Constant Rands (June 2010) using the Consumer Price Index to allow for comparison in real
terms over time.
In the first 10 years of implantation the average estimated costs incurred by adult implantees
totalled R379 626, and children R455 225. The findings showed that the initial purchase of the
implant system was the most substantial cost involved (currently R221 000). Upgrading the
speech processor, which on the average took place every 7 years, was the second highest
cost subjects encountered (currently R85 000). The cost of spares (on average R276 per
year) and repairs (R3000 per repair) increased with duration of use. Battery costs ranged
between R1200 and R3372 per year and insurance costs averaged R4040 per year.
Most appointments took place in the first two years following implantation. Average travel
costs during the first two years were R1024 for those within 50km of the implant unit and
R8645 for those living more than 1000km away. Accommodation costs for non-local
recipients, peaked during this period (on average R3390). Additional rehabilitation services for
paediatric implantees cost an estimated R37 159 in the first five years after implantation.
Subjects advised potential implantees to save, budget and plan for the high costs involved in
implantation, as well as to join a medical aid which could assist with the costs involved. The findings of the study hold great relevance for both implantees and cochlear implant
professionals. Careful consideration of the financial implications of cochlear implantation is
critically important in the South African context to ensure that recipients are successful longterm
cochlear implant users. Although the actual costs in the study were related to the one
implant system used at Tygerberg Hospital-University of Stellenbosch Cochlear Implant Unit,
it is believed that the types and amounts of costs involved hold relevance for all individuals
implanted in South Africa.<br>AFRIKAANSE OPSOMMING: Kogleêre inplantering is ‘n duur maar koste-effektiewe prosedure wat lewenslank gebruik
moet word. Dit verskaf aan individue met erge-tot-uitermatige gehoorverlies verbeterde
klankpersepsie in vergelyking met dié wat gehoorapparate gebruik. In Suid Afrika word
kogleêre inplantings nie deur die staat gesubsidieer nie en koste moet deur die
inplantgebruiker verhaal word. Kogleêre inplantingspanne moet gevolglik verseker dat
individue wat geselekteer word daarby baat sal vind en lewenslank sal kan gebruik.
Inplantgebruikers moet bewus wees van die onmiddelike, sowel as langtermyn onkoste.
Die primêre doel van hierdie studie was om die onmiddelike en langtermyn onkoste van
implanterings te bepaal. Een honderd vier en vyftig inplantgebruikers van die Tygerberg
Hospitaal-Universiteit Stellenbosch Kogleêre Inplantingseenheid in Kaapstad, Suid Afrika is
gebruik vir die studie. Onkoste was gekatogoriseer ten opsigte van die periode van tyd postinplantering
en dit is omgeskakel na konstante Randwaarde (Junie 2010) deur die Gebruikers
Prys Indeks te gebruik sodat vergelykings gemaak kon word in reële terme oor tyd.
Gedurende die eerste 10 jaar na inplantering was die geskatte onkoste by volwasse
inplantgebruikers R379 626 en by die pediatriese groep was dit R455 225. Bevindings het
aangedui dat die aanvanklike aankoop van die inplantsisteem die grootste onkoste behels het
(huidig R221 000). Opgradering van die prosesseerder, gemiddeld elke 7 jaar, was die
tweede hoogste onkoste, naamlik R85 000. Die gemiddelde koste van spaaronderdele was
R276 per jaar. Herstelkoste het R3000 per herstelling beloop. Koste van spaaronderdele en
herstelkoste het met duur van gebruik vermeerder. Batteryonkoste het gewissel tussen
R1200 en R3372 per jaar. Onkoste van jaarlikse versekering was gemiddeld R4040.
Meeste afsprake het gedurende die eerste twee jaar plaasgevind. Vervoeronkoste gedurende
hierdie periode was R1024 vir die wat binne 50km woon en R8645 vir dié meer as ‘n 1000km
ver. Akkommodasie koste het ‘n piek gedurende hierdie periode bereik (gemiddeld R3390).
Addisionele rehabilitasie dienste vir pediatriese inplantgebruikers was gemiddeld R37159
gedurende die eerste vyf jaar. Die proefpersone het aanbeveel dat potensiële
inplantgebruikers moet spaar, begroot en beplan vir die hoë onkoste en is aanbeveel om aan
te sluit by ‘n mediese fonds. Die bevindinge van die studie is van belang vir beide ontvangers sowel as inplantingspanne.
Bewusmaking van die finansiële implikasies van kogleêre inplantering is van kritiese belang
om suksesvolle langtermyn gebruik te verseker. Alhoewel die werklike onkoste in die studie
van toepassing is op een inplanting sisteem wat by Tygerberg Hospitaal-Universiteit
Stellenbosch Kogleêre Inplantingseenheid gebruik word, kan dit aangeneem word dat die
tipes en hoeveelheid onkoste van toepassing is op alle individue in Suid Afrika wat kogleêre
inplantings ontvang.
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Patil, Gaurav. "Stewart Platform Actuator for Direct Access Cochlear Implant." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439296078.
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Le, Roux Talita. "Predictors of cochlear implant outcomes in South Africa." Thesis, University of Pretoria, 2016. http://hdl.handle.net/2263/60377.
Full textAbstract:
This research focused on the identification and description of predictors of pediatric and
adult cochlear implantation outcomes in a South African cohort and the depiction of
profound childhood hearing loss in terms of risk and intervention profiles.
Study I described profound childhood hearing loss in a South African cohort of pediatric
cochlear implant (CI) recipients in terms of risk profile and age of diagnosis and intervention.
A retrospective review of patient files for 264 pediatric CI recipients from five CI programs
was conducted. For all subjects, permanent congenital and early onset hearing loss (PCEHL)
was confirmed under the age of five years old.
The most prevalent risks for profound PCEHL were neonatal intesive care unit (NICU)
admittance (28.1%), family history of childhood hearing loss (19.6%) and prematurity
(15.1%). An associated syndrome was diagnosed in 10% of children and 23.5% had at least
one additional developmental condition. Hearing loss for most (77.6%) children was
confirmed as congenital or early onset, while 20.3% presented with postnatal onset of
hearing loss. Auditory Neuropathy Spectrum Disorder (ANSD) was diagnosed in 5% of
children, with admittance to NICU (80%) and hyperbilirubinemia (50%) being the most
prevalent risk factors for these cases. Hearing loss was typically diagnosed late (15.3
months), resulting in delayed initial hearing aid fitting (18.8 months), enrollment in early
intervention services (19.5 months), and eventual cochlear implantation (43.6 months).
Delayed diagnosis and intervention predispose this population to poorer outcomes.<br>Thesis (DPhil)--University of Pretoria, 2016.<br>Speech-Language Pathology and Audiology<br>DPhil<br>Unrestricted
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Celliers, Liani. "Communication-related outcomes of cochlear implant use by late-implanted prelingually deafened adults." Diss., Pretoria : [s. n.], 2009. http://upetd.up.ac.za/thesis/available/etd-02222010-142944.
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Deshpande, Shruti. "Characterization of Cochlear Implant related Artifact during Sound-Field Recording of the Auditory Steady State Response (ASSR): A Comparison between Normal Hearing Adults, Cochlear Implant Recipients and Implant-in-a-Box." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406820669.
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Aisha, Rani. "Tone perception of Cantonese-speaking children with cochlear implant." Click to view the E-thesis via HKUTO, 2000. http://sunzi.lib.hku.hk/hkuto/record/B3620738X.
Full textAbstract:
Thesis (B.Sc)--University of Hong Kong, 2000.<br>"A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, May 10, 2000." Also available in print.
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Chan, Tsz-kwan. "Cantonese tone perception by postlingually deaf cochlear implant users." Click to view the E-thesis via HKUTO, 2001. http://sunzi.lib.hku.hk/hkuto/record/B36207780.
Full textAbstract:
Thesis (B.Sc)--University of Hong Kong, 2001.<br>"A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, May 4, 2001. Also available in print.
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Reich, Rebecca Danielle 1977. "Instrument identification through a simulated cochlear implant processing system." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/62373.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002.<br>Includes bibliographical references (p. 97-99).<br>The signal processing used by cochlear implants is primarily designed to convey speech and environmental sounds, and can cause distortion of music. Although some studies of implanted listeners have demonstrated their limited ability to identify instruments, these results do not suggest whether the sound-processing system or the subjects' physiological state is the limiting factor. In this research, normal-hearing subjects determined the extent to which a simulation of the sound processing of a common cochlear implant degraded their ability to recognize instruments. The signal processing simulated in this study included bandpass filtering, rectification and lowpass filtering. Musical signals consisting of acoustic and synthetic solo instrument performances of short phrases were passed through the simulation, and presented to 25 normal-hearing participants as part of an instrument identification task. Eight acoustic and eleven synthesized common instrument timbres were used as input signals to the simulation and two rectification methods were studied for comparison purposes. Subjects were asked to identify the instrument presented, for the unaltered sounds and the sounds processed by the simulation. Identification scores for sounds heard through the simulation were significantly lower than those for unaltered sounds, due to the limited time and frequency information transmitted by the processing scheme. The results support the hypothesis that it is necessary to pursue alternative processing schemes for the implant, specifically intended for music-listening purposes.<br>by Rebecca Danielle Reich.<br>S.M.
29
Grange, Jacques. "Realising the head-shadow benefit to cochlear implant users." Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/73116/.
Full textAbstract:
Cochlear implant (CI) users struggle to understand speech in noise. They suffer from elevated hearing thresholds and, with practically no binaural unmasking, they rely heavily on better-ear listening and lip reading. Traditional measures of spatial release from masking (SRM) quantify the speech reception threshold (SRT) improvement due to the azimuthal separation of speech and interferers when directly facing the speech source. The Jelfs et al. (2011) model of SRM predicts substantial benefits of orienting the head away from the target speech. Audio-only and audio-visual (AV) SRTs in normally hearing (NH) listeners and CI users confirmed model predictions of speech-facing SRM and head-orientation benefit (HOB). The lip-reading benefit (LRB) was not disrupted by a modest 30° orientation. When attending to speech with a gradually diminishing speech-to-noise-ratio (SNR), CI users were found to make little spontaneous use of their available HOB. Following a simple instruction to explore their HOB, CI users immediately reached as much as 5 dB lower SNRs. AV speech presentation significantly inhibited head movements (it nearly eradicated CI users’ spontaneous head turns), but had a limited impact on the SNRs reached post-instruction, compared to audio-only presentation. NH listeners age-matched to our CI participants made more spontaneous head turns in the free-head experiment but were poorer than CI users at exploiting their HOB post-instruction, despite their exhibiting larger objective HOB. NH listeners’ and CI users’ LRB measured 3 and 5 dB, respectively. Our findings both dispel the erroneous beliefs held by CI professionals that facing the speech constitutes an optimal listening strategy (whether for lip-reading or to optimise the use of microphone directionality) and pave the way to obvious translational applications.
30
Verschuur, Carl. "Acoustic models of consonant recognition in cochlear implant users." Thesis, University of Southampton, 2007. https://eprints.soton.ac.uk/51152/.
Full textAbstract:
Normal-hearing adults have no difficulty in recognising consonants accurately, even in moderately adverse listening conditions. By contrast, users of multichannel cochlear implants have difficulty with the accurate perception of consonants, even in good listening conditions. Cochlear implant users are known to show systematic deficits in recognition of consonant features, with perception of the place feature, which relies on spectral information, being worst. These deficits may be attributed both to signal distortions introduced by the processing of the implants and to other factors, in particular the spectrotemporal distortions which occur at the interface between electrode array and auditory nervous system, including cross-channel interaction. The objective of the work reported here was to attempt to partial out the relative contribution of these different factors to consonant recognition. This was achieved by comparing cochlear implant users’ perceptual errors, analysed in terms of information transmission, with errors made by normal-hearing subjects listening to acoustic models of implant processing, in various conditions. Two initial experiments were undertaken to develop and refine an acoustic model of the Nucleus 24 cochlear implant. Findings from these two experiments informed the design of the main acoustic model experiment, which was undertaken in parallel with a further experiment involving users of the Nucleus 24 device. In both experiments, subjects listened to nonsense syllables with and without the addition of stationary background noise, in three different configurations of implant processing parameters. Additionally, in the acoustic model experiment, a simulation of cross-channel spread of excitation, or “channel interaction”, was varied. Results showed that acoustic model experiments were predictive of the pattern of consonant feature transmission in cochlear implant users with better baseline consonant recognition scores. Deficits in consonant recognition in this subgroup could be explained by the loss of phonemically relevant acoustic information in speech due to the nature of cochlear implant processing, while channel interaction appeared to play a smaller role in accounting for problems in consonant recognition. The work also evaluated the effect of changes in channel number and stimulation rate and failed to find any changes in consonant recognition as these parameters were varied. The lack of a stimulation rate effect was consistent with acoustic measurements of the temporal modulation transfer function of the processor, which showed almost no change across stimulation rates.
31
Liang, Chun Ph D. "Cortical Representation of Frequency Changes in Cochlear Implant Users." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1504796317530661.
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Müller-Deile, Joachim. "Verfahren zur Anpassung und Evalution von Cochlear-implant-Sprachprozessoren." Heidelberg Median-Verl. von Killisch-Horn, 2008. http://d-nb.info/992548535/04.
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Leigh, Braden Lynn. "Engineering surfaces using photopolymerization to improve cochlear implant materials." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6176.
Full textAbstract:
Cochlear implants (CIs) help to restore basic auditory function in patients who are deaf or have profound hearing loss. However, CI patients suffer from limited voice and tonal perception due to spatial separation between the stimulating CI electrode and the receptor spiral ganglion neurons (SGNs). Directed regeneration of proximate SGN axons may improve tonal performance and implant fidelity by decreasing the spatial separation between the CI electrode and the neural receptor. Additionally, fibrous scar tissue formation on the surface of implanted electrodes further decreases tonal perception through current attenuation and spreading resulting in late-term hearing loss. Thus, designing surfaces that induce favorable responses from neural tissues will be necessary in overcoming signal resolution barriers. In this work, the inherent spatial and temporal control of photopolymerization was used to functionalize surfaces with topographical and biochemical micropatterns that control the outgrowth of neural and other cell types. First, laminin, a cell adhesion protein was patterned using a photodeactivation process onto methacrylate polymer surfaces and was shown to direct the growth of spiral ganglion neurons (SGN), the primary auditory neural receptors. These protein patterns could even overcome low amplitude/high periodicity competing topographical cues. Additionally, glass substrates were patterned with linear zwitterionic polymers and fibroblasts, astrocytes, and Schwann cells all showed dramatically decreased cell adhesion on 100 µm precocity patterns. Further, SGN neurites showed excellent alignment to these same patterns. Next, poly(dimethyl siloxane) (PDMS) was coated with a crosslinked zwitterionic thin film using a single step photografting/photopolymerization process to covalently bind the hydrogel to PDMS. These coated surfaces showed dramatically lower levels of protein, cell, and bacterial adhesion. Finally, zwitterionic hydrogels were strengthened by changing the concentration of poly(ethylene glycol) diacrylate (PEGDA) and 2-hydroxyethyl methacrylate (HEMA) in the formulation. The direct relationship between changing zwitterionic hydrogel formulation to strengthen the hydrogel and the anti-fouling properties were established. The fundamental understanding and design of cochlear implant materials described herein serves as a foundation for the development of next generation neural prosthetics.
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Ross, Carol F. "Some effects of cochlear implant use on loudness modulation." PDXScholar, 1985. https://pdxscholar.library.pdx.edu/open_access_etds/3524.
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In this study, five deaf individuals with cochlear implants were presented with noise that was manipulated systematically, to test the hypothesis that deaf persons using cochlear prostheses will demonstrate intensity regulation of their vocal output that is more appropriate when their implants are turned on than when turned off. The intensity of their vocal output was measured to determine if they demonstrated a Lombard response, that is, a systematic increase in vocal intensity with increasing intensity of background noise. Results from the study were mixed. With implants on, three subjects made systematic increases in vocal intensity with increasing background noise, while two subjects did not make such increases. In addition, the relation between intensity of vocal output and background noise was closer to the normal function for the three subjects who demonstrated a Lombard response. The "normal function" was defined by measuring the vocal intensity responses of five normal hearing control subjects who performed the same tasks as the experimental subjects.
35
Yuen, Wing-ka Charlotte. "Production of stop consonants by Cantonese-speaking cochlear implant users." Click to view the E-thesis via HKU Scholars Hub, 2007. http://lookup.lib.hku.hk/lookup/bib/B42006272.
Full textAbstract:
Thesis (B.Sc)--University of Hong Kong, 2007.<br>"A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2007." Includes bibliographical references (p. 27-30). Also available in print.
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Figueroa, González Mario. "La comprensión lectora: relación con la teoría de la mente y las funciones ejecutivas. Estudio comparativo en adolescentes con implante coclear y con desarrollo típico." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/671661.
Full textAbstract:
El benefici obtingut per la població amb sordesa de l'implant coclear (IC) ha traslladat nous reptes a la comunitat científica i educativa. La millora de la competència lectora al nivell dels seus parells amb desenvolupament típic (DT) és un dels objectius més importants dels logopedes a l'actualitat. La lectura és una eina bàsica per al desenvolupament de cada individu, especialment en l'adolescència quan es converteix en el principal mitjà d'aprenentatge. No obstant això, l'enfocament que se li dóna a la lectura en el cas de l'alumnat amb IC continua sent fonamentalment lingüístic. A més dels aspectes lingüístics ja coneguts que podrien estar implicats en la comprensió lectora, alguns estudis previs en l'alumnat amb DT han pogut trobar relacions amb altres factors com la teoria de la ment (TM) i les funcions executives (FFEE). L'alumnat amb una menor habilitat mentalista o executiva, com podria ser l'alumnat amb IC, podria tenir més dificultats per aplicar TM durant la lectura per comprendre les emocions dels personatges o per autoregular la seva lectura a través de les FFEE. En aquest sentit, en el present treball es van formular diferents objectius. D'una banda, es va comparar el rendiment en la comprensió lectora, la teoria de la ment i les funcions executives de l'alumnat amb IC i de l'alumnat amb DT. D'altra banda, es va analitzar la relació entre la comprensió lectora i la TM, així com la relació entre la comprensió lectora i les FFEE. En l'estudi van participar 36 estudiants amb IC i 54 estudiants amb DT que van ser avaluats mitjançant la bateria de lectura PROLEC, la prova de Stroop (inhibició), la prova de Plus-minus (canvi), la prova de memòria de lletres (actualització de la memòria), les proves de memòria de treball visual i auditiva, una prova de falsa creença i una prova de ficades de pota. Els resultats van mostrar que el grup amb IC va obtenir un rendiment més baix que el grup amb DT en els diferents textos utilitzats i, de la mateixa manera, l'alumnat amb IC també va tenir més dificultats per aplicar la TM de forma adequada. Els resultats de les proves neuropsicològiques tan sols van mostrar que l'alumnat amb IC va executar de manera similar als seus parells amb DT la tasca d'inhibició i de canvi. No obstant això, l'anàlisi de les condicions auditives suggereix que l'alumnat amb condicions auditives òptimes podria tenir una competència lectora, mentalista i executiva similar a la del grup amb DT. Les anàlisis de regressió també mostra que l'alumnat amb IC sembla necessitar una contribució més gran de la TM i de les FFEE per comprendre un text.<br>El beneficio obtenido por la población con sordera del implante coclear (IC) ha trasladado nuevos retos a la comunidad científica y educativa. La mejora de la competencia lectora al nivel de sus pares con desarrollo típico (DT) es uno de los objetivos más importantes de los logopedas en la actualidad. La lectura es una herramienta básica para el desarrollo de cada individuo, especialmente en la adolescencia cuando se convierte en el principal medio de aprendizaje. Sin embargo, el enfoque que se le da a la lectura en el caso del alumnado con IC continúa siendo fundamentalmente lingüístico. Además de los aspectos lingüísticos ya conocidos que podrían estar implicados en la comprensión lectora, algunos estudios previos en el alumnado con DT han podido encontrar relaciones con otros factores como la teoría de la mente (TM) y las funciones ejecutivas (FFEE). El alumnado con una menor habilidad mentalista o ejecutiva, como podría ser el alumnado con IC, podría tener mayores dificultades para aplicar TM durante la lectura para comprender las emociones de los personajes o para autoregular su lectura a través de las FFEE. En este sentido, en el presente trabajo se formularon diferentes objetivos. Por un lado, se comparó el rendimiento en la comprensión lectora, la teoría de la mente y las funciones ejecutivas del alumnado con IC y del alumnado con DT. Por otro lado, se analizó la relación entre la comprensión lectora y la TM, así como la relación entre la comprensión lectora y las FFEE. En el estudio participaron 36 estudiantes con IC y 54 estudiantes con DT que fueron evaluados mediante la batería de lectura PROLEC, la prueba de Stroop (inhibición), la prueba de Plus-minus (cambio), la prueba de memoria de letras (actualización de la memoria), las pruebas de memoria de trabajo visual y auditiva, una prueba de falsa creencia y una prueba de meteduras de pata. Los resultados mostraron que el grupo con IC obtuvo un rendimiento más bajo que el grupo con DT en los diferentes textos utilizados y, del mismo modo, el alumnado con IC también tuvo mayores dificultades para aplicar la TM de forma adecuada. Los resultados de las pruebas neuropsicológicas tan sólo mostraron que el alumnado con IC ejecutó de manera similar a sus pares con DT la tarea de inhibición y de cambio. Sin embargo, el análisis de las condiciones auditivas sugiere que el alumnado con condiciones auditivas óptimas podría tener una competencia lectora, mentalista y ejecutiva similar a la del grupo con DT. Los análisis de regresión también muestra que el alumnado con IC parece necesitar una contribución mayor de la TM y de las FFEE para comprender un texto.<br>The benefit obtained by the people with hearing loss from the cochlear implant (CI) has brought new challenges to the scientific and educational community. Improving reading skills at the level of their typically developing peers (TD) is one of the most important goals for speech therapists up to now. Reading is a basic tool for the development of each individual, especially in adolescence when students read to learn. However, the investigators in reading continue to focus basically in some linguistic aspects in the case of adolescents with CI. In addition to the well-known linguistic aspects that could be involved in reading comprehension, some previous studies in students with TD have been able to find relationships with other factors such as theory of mind (TM) and executive functions (EF). Students with less mentalistic or executive ability, such as students with a CI, could have greater difficulties during reading to understand the emotions of the characters or to self-regulate their reading through EF. In this sense, different aims were formulated in this thesis. On the one hand, the performance in reading comprehension, ToM and EF of students with CI and students with TD were compared. On the other hand, the relationship between reading comprehension and TM was analyzed, as well as the relationship between reading comprehension and EF. The study recruited 36 students with CI and 54 students with DT who were evaluated with the PROLEC reading battery, the Stroop test (inhibition), the Plus-minus task (switching), the letter-memory task (updating), visual and auditory working memory tasks, a false belief, and a Faux Pas test. The results showed that the group with CI obtained a lower performance than the group with TD in the different texts used and, in the same way, the students with CI also had greater difficulties to solve ToM tasks in an adequate way. The results of the neuropsychological tests only showed that students with CI performed inhibition and switching task in a similar way to their peers with TD. However, better auditory conditions could enhance EF and linguistic competence. Regression analysis show that students with CI seem to need a greater contribution from TM and EF to understand a text.
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She, Jennifer Heep Kwan. "Perception of music for adult cochlear implant users: a questionnaire." Thesis, University of Canterbury. Department of Communication Disorders, 2008. http://hdl.handle.net/10092/1584.
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Existing music questionnaires have shown that postlingually deafened adult cochlear implant (CI) users generally find music to be less enjoyable following implantation. However, they did not investigate, in detail, which factors influence CI users’ music listening enjoyment, nor did they examine the approach a music training program should take. In order to obtain such information, a questionnaire, the University of Canterbury Music Listening Questionnaire (UCMLQ), was developed. The UCMLQ investigated: (i) the effect of implantation on CI users’ music listening enjoyment (determined by comparing the levels of enjoyment experienced post-implantation to prehearing loss, and just before implantation); (ii) the effect of a hearing aid in the unimplanted ear on CI users’ music perception and appreciation; (iii) the effect of timbre on music listening enjoyment whereby respondents will be asked to rate the pleasantness and naturalness of common instruments and voices, and also, give ratings on the instruments’ sound quality based on what they expect these instruments to sound to a person with normal hearing; (iv) whether respondents have a preference for a particular musical style (e.g. Country and Western, Jazz, Classical, etc); (v) whether respondents’ have a preference for, firstly, low-pitched versus high-pitched instruments/voices; secondly, music with instruments-only, voice-only, or both instruments and voice; and lastly, music with smaller number of performers versus greater number of performers; (vi) practical methods or ‘tips’ for enhancing everyday music listening enjoyment were collated; and finally, (vii) respondents were asked for their views and opinions on the content and logistics of a ‘take-home’ MTP for improving their music listening enjoyment. One-hundred postlingually deafened adult CI users, ranging in age from 18 to 88 years (mean = 62.1, SD = 17.1), completed the UCMLQ. All respondents used a Nucleus CI24 implant and the ACE speech processing strategy. Results showed that following implantation, respondents generally found music to be less enjoyable but they also preferred certain types of instruments and music: (i) low-frequency instruments over high-frequency instruments; (ii) certain instruments (e.g. the guitar) over others (e.g. brass instruments); (iii) smaller numbers of performers as opposed to larger numbers; (iv) Country and Western music as opposed to Pop/Rock, Jazz, Classical-small group, and Classical-orchestra; and (v) music with a slow rhythm/beat, and words. A comparison of the ratings given by CI and Hearing Aid (CI+HA) users and CI-only users also revealed that CI+HA users felt that they were significantly more able to follow the melody-line of musical styles, identify these styles, and they also rated musical styles to sound significantly ‘more normal’ than the CI-only users did. However, no statistically significant difference was found between the two groups’ (CI+HA users versus CI-only users) ratings for common instrumental sounds. In regards to respondents’ interest in partaking in a ‘take-home’ music training program (MTP), 54% of respondents stated that they would be interested in undertaking one. Respondents also indicated that the MTP should focus on improving their ability to recognise tunes, in particular, tunes known before implantation, and commonly-known tunes, and the MTP should offer a wide range of musical styles. In addition, training sessions should be of 30- minutes duration, 2 times per week, and the MTP should come in the form of a DVD with subtitles. Overall, this study collected information which not only helps us to better understand CI users’ appreciation of music but also could be used in the shaping and development of a future MTP.
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Agrawal, Deepashri [Verfasser]. "Prosody perception in cochlear implant users: EEG evidence / Deepashri Agrawal." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2013. http://d-nb.info/103209947X/34.
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Lim, Stacey R. "Evaluating speech-in-noise performance of bilateral cochlear implant recipients." Thesis, Kent State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618872.
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<p> The goal of this study was to determine whether sequentially acquired bilateral implants provide improved speech understanding relative to performance with unilateral implants in varying sound source configurations that may more closely represent daily listening environments. Participants were divided into higher and lower performance groups based upon their best unilateral performance on monosyllabic words in quiet and asked to repeat Bamford-Kowal-Bench Speech-in-Noise (BKB-SIN) sentences in unilateral and bilateral listening conditions. The sentences were always presented from directly in front, while competing noise was presented from varying locations. Results indicated that the bilateral listening condition yielded significantly better scores compared to the unilateral listening condition across all participants, with the higher performance group's scores significantly better than for the lower performance group. Both groups had similar gains in performance. No significant differences were observed amongst sound sources, contrary to the original hypothesis. Among demographic variables, only unilateral performance on words in quiet and onset of deafness were highly correlated with bilateral performance. As the initial grouping variable addressed performance in quiet, a second analysis regrouped participants by onset of deafness (pre- vs. postlingual) This regrouping yielded even greater group differences overall, and some noise configurations were now significantly different for the postlingually deafened participants. Taken together, these results suggest that postlingually deafened participants may be able to use higher level binaural processes established prior to deafness and not available to prelingually deafened listeners.</p>
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Dritsakis, Giorgos. "The 'music-related quality of life' of cochlear implant users." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/413587/.
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Outcome measures for adult cochlear implant (CI) users are needed to evaluate music rehabilitation tools. Music questionnaires developed for CI users may capture real-world music experiences better than music perception tests but have not been designed to measure outcomes. A new reliable and valid instrument measuring a wide range of music experiences and the impact of music on the quality of life (QOL) of adult CI users could be more appropriate for the assessment of music rehabilitation. This PhD thesis made steps towards the development of such a measure. Music-related Quality of Life (MRQOL) was defined as a function of music experiences and their importance in life. On the basis of this concept, two initial pools of questionnaire items were developed, one assessing musical abilities, attitudes and activities and another one assessing their importance. The items were generated using focus group data from 30 adult CI users and reviewed by 24 professionals for face validity and refinement. After completion of both sets of questions by 147 adult CI users, 18 items were selected for each set with the use of traditional psychometric techniques. The items grouped together into two meaningful domains (perception and engagement) with high reliability and some evidence for construct validity. Scores of ‘music perception and engagement’ and importance for the 18 items can be combined to measure the impact of music on QOL. The meaning of individual ‘impact’ scores and the ability of the questionnaire to measure changes have to be further studied. This thesis broadens the understanding of CI users’ relationship with music and the effects of music on their QOL. Novel aspects of music experience were identified. The MRQOL measure has the potential to become a standard measure of music-specific outcomes and of the impact of music on the QOL of adult CI users and hearing-impaired adults in general, with potential clinical utility.
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Grasmeder, Mary. "Optimising frequency-to-electrode allocation for individual cochlear implant users." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/397271/.
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Pitch perception for cochlear implant (CI) users is known to vary between individuals due to differences of insertion depth, of the function of neural tissue in the cochlea, of acclimatisation and CI stimulation parameters. In this study, frequency-to-electrode allocation was adjusted in a group of 12 adult cochlear implant users, to ascertain if the use of a default setting results in optimum perception of speech and music for individual recipients. Participants in the experiment trialled a map in which the frequency allocation was adjusted to the frequency-position function of the normal cochlea and a map which allocated sounds to a limited area of the cochlea, in addition to the default. Performance with the two alternative maps did not exceed that of the default allocation and was poorer for the majority of participants: [F(2,14) = 51.3, p<0.001] for a sentence test in noise. Performance was negatively correlated with the magnitude of the adjustment from the default [r=0.838, p=0.002 and r=-0.700, p=0.024] for the two maps, suggesting that participants had acclimatised to their clinical maps. Electrode discrimination was found to be at chance levels for some participants at the apical end of the array but above chance in the middle of the array. Another alternative map, with logarithmic frequency spacing and some basal shift was trialled and gave improved performance on a sentence test in noise for three participants with poor electrode discrimination at the apical end of the array. A second experiment was conducted, with 13 adult CI users, in which perception of speech and music was assessed with ten frequency allocations, including the default. The ability to follow a pitch contour was measured for centre frequencies of neighbouring filters. Performance with the different allocations varied between individuals; some individuals performed better with alternative allocations from the default. A strategy was developed for the selection of frequency allocation for individuals, based on pitch contour scores for different electrodes, which offered improved performance on the sentence test for the group [t(12)=-3.31, p=0.006, r=0.69]. The overall results show that optimisation of frequency allocation for individuals can be achieved by adjustment of the frequency-to-electrode allocation based on pitch perception ability in different areas of the cochlea.
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Eby, Christine A. "Pediatric Cochlear Implant Outcomes in Auditory Neuropathy/Auditory Dys-Synchrony." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1085691784.
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KANT, ANKUR. "DESIGN AND PATTERNING OF POLY-PYRROLE INTERCONNECTS FOR COCHLEAR IMPLANT." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1147376799.
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Lim, Stacey. "Evaluating Speech-in-Noise Performance of Bilateral Cochlear Implant Performance." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1373833599.
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Gedeon, Ibrahim Joseph Carleton University Dissertation Engineering Electrical. "Cepstral analysis : a speech processing strategy for the cochlear implant." Ottawa, 1990.
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Van, Zyl Joe. "Objective determination of vowel intelligibility of a cochlear implant model." Pretoria : [s.n.], 2009. http://upetd.up.ac.za/thesis/available/etd-03082009-174318/.
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JAHNKE, MARGARET L. "QUALITATIVE ANALYSIS OF THE BENEFITS OF COCHLEAR IMPLANTS FOR CHILDREN WITH MULTIPLE HANDICAPS." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1084200167.
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Jia, Huan. "Stratégies pharmacologiques pour la prévention de la fibrose intra-cochléaire." Thesis, Montpellier 1, 2012. http://www.theses.fr/2012MON1T001.
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L'implantation cochléaire reste à ce jour le seul moyen capable de restaurer la perception auditive chez les personnes présentant une surdité sévère ou profonde en échec d'appareillage conventionnel. Son principe repose sur la stimulation électrique directe des neurones auditifs de la cochlée par un faisceau d'électrode inséré dans l'oreille interne. Malgré les progrès réalisés dans le manufacturage des électrodes et dans la technique chirurgicale, le geste d'insertion du faisceau d'électrode demeure traumatique. Ce traumatisme est souvent responsable de la perte de l'audition résiduelle sur les fréquences graves et d'une réaction inflammatoire conduisant à une cicatrisation fibreuse. Cette réaction fibreuse est délétère à la fois pour le fonctionnement de l'implant, car augmentant l'impédance des électrodes, mais aussi pour l'audition résiduelle lorsqu'elle est préservée, limitant ainsi les possibilités de stimulation hybride électro-acoustique. Aussi les recherches actuelles tendent à réduire cette fibrose par des moyens pharmacologiques limités, utilisant un corticoïde (dexaméthasone), sans pour autant que son efficacité n'ait été démontrée de manière formelle in vitro ou in vivo. En outre, les cibles moléculaires visées lors de la réaction inflammatoire et fibrotique dans la cochlée n'étant pas clairement identifiées, il est difficile de savoir si cette approche thérapeutique est la plus adaptée. Dans ce travail nous avons donc mis au point des modèles in vitro de culture de tranche de cochlée et d'explant cochléaire de rat pour tester l'efficacité antifibrotique et la toxicité de plusieurs drogues, dont la dexaméthasone, mais aussi l'aracytine, antimitotique non ototoxique et d'utilisation sûre au contact du système nerveux central. Entre nos mains, il apparaît que la stratégie antimitotique par application d'aracytine était plus efficace contre la fibrose et moins toxique pour les cellules sensorielles que la dexamethasone. Dans une seconde partie de ce travail, nous avons utilisé deux modèles in vivo de fibrose cochléaire, à savoir : l'induction d'une labyrinthite immune à Keyhole Limpet Hemocyanin et l'implantation chronique d'un corps étranger intra-cochléaire. A nouveau, l'aracytine délivrée par pompe osmotique intracochléaire permettait de réduire significativement la fibrose dans le modèle de labyrinthite alors que l'effet de la dexamethasone n'était pas significatif. De même la préservation de l'audition était statistiquement meilleure dans le groupe des animaux traités par antimitotiques. Aussi seule l'aracytine a été testée dans l'autre modèle de corps étranger intracochléaire. Elle permettait également de réduire la fibrose observée dans la cochlée, sans effet toxique sur les neurones auditifs. Si la préservation de l'audition était impossible dans le groupe contrôle, l'audition sur les basses fréquences était conservée chez les animaux traités par aracytine. Enfin, les seuils de stimulation électrique capables de provoquer une réponse électrophysiologique par le potentiel évoqué auditif étaient significativement inférieurs dans le groupe traité par aracytine. Ainsi, nous avons pu montrer qu'une stratégie antimitotique était capable d'inhiber efficacement la fibrose dans la cochlée in vitro et in vivo, et ce avec une efficacité supérieure à la dexaméthasone. Nous recommandons donc d'envisager en pratique clinique l'utilisation de l'aracytine pour prévenir la fibrose cochléaire. De plus, ce travail souligne l'intérêt de mieux décortiquer les voies cellulaires conduisant à l'inflammation et à la fibrose cochléaire, de sorte à déterminer les meilleures cibles et molécules candidates. Ces mêmes molécules pourront être testées sur les modèles que nous avons mis au point afin de proposer de nouvelles alternatives thérapeutiques à la prévention de la fibrose cochléaire<br>Cochlear implantation is the only treatment capable of restoring the auditory pathways in patient suffering from severe to profound hearing loss with poor benefit from hearing aids. Its functioning relies on direct electric stimulation of primary auditory neurons through an electrode array inserted into the cochlea.Despite the advances in electrode design and surgical technique, the act of inserting the electrode array is still traumatic. These traumas result in the loss of residual hearing in low frequencies and provoke an inflammatory reaction leading to fibrous scarring. This fibrous reaction is deleterious to not only the implant performance by increasing the impedance of the electrodes, but also the preserved residual hearing which limit the possibilities of hybrid electro-acoustic stimulation.Current researches aim at limiting this fibrosis by drug application, such as corticosteroids. Therefore dexamethasone is frequently used, but its effectiveness has been only demonstrated formally in vitro or in vivo. Furthermore, the molecular targets set in the fibrotic and inflammatory reaction in the cochlea are not clearly identified, and it is unclear whether this therapeutic approach is best suited.In this study we have developed in vitro models of rat cochlear slice and cochlear explants culture to test the antifibrotic efficacy and toxicity of various drugs, including dexamethasone, but also aracytine, an antimitotic drug with very low ototoxicity which is safely used in contact with the central nervous system. In our hands, it appears that antimitotic aracytine is more effective against fibrosis and less toxic to the sensory cells than the anti-inflammatory drug dexamethasone.In the second part of this study, we used two in vivo models of cochlear fibrosis namely the KLH(keyhole limpet hemocyanin)-induced sterile labyrinthitis and the foreign-body-induced chronic labyrinthitis. Again, the intracochlear fibrosis in the model of KLH-induced labyrinthitis was signticantly reduced by the osmotic pump with aracytine, while the effect of dexamethasone was not significant. Also the preservation of the hearing was statistically better in the group of animals treated with this antimitotic drug. Consequently, aracytine was the only drug tested in the other model of foreign-body-induced labyrinthitis. Again, aracytine reduced fibrosis in the cochlea, without any toxic effects on auditory neurons. While the preservation of the hearing was not achieved in the control group, the low frequencies hearing was preserved in animals treated with aracytine. Finally, the thresholds of electrical stimulation eliciting auditory brainstem response recordings were significantly lower in the treated group by aracytine.Thus, we have shown that an antimitotic strategy was able to inhibit fibrosis effectively in the cochlea in vitro and in vivo, and this with a greater efficiency than dexamethasone. We therefore recommend considering in clinical practice the use of aracytine to prevent cochlear fibrosis. In addition, this study stresses the importance of analyzing the cellular pathways of cochlear inflammation and fibrosis, in order to determine the best targets and candidate molecules. These molecules could be tested on the models that we have developed in order to offer new therapeutic options to prevent cochlear fibrosis
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Zhang, Yu. "Investigation of cochlear disturbance induced during surgical intervention." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/16920.
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Hearing loss is a common impairment or disability for human beings, and is impacting an increasing amount of people, augmented by the growing aging population around the globe. Cochlear implantation, as one of the most effective ways to restore hearing, can only applied to profoundly deaf patients at the moment. In order to expand the group of people who can benefit from cochlear implantation to those with less severe hearing loss, endeavours need to be made to best preserve residual hearing and minimise trauma induced during cochlear implantation surgery. In this thesis, the disturbance induced in the cochlea, i.e. the acoustic and mechanical energy transmitted into the cochlea, during cochleostomy drilling is studied - as well as establishing a comparison between a manually guided conventional technique and a manually supported tissue guided robotic drilling technique. The results show that by changing surgical techniques and how they are applied can have a significant impact on levels of disturbance induced - robotic-aided approach induced lower level of equivalent SPL for up to 86% of the time and can be as much as 39 dB lower than that generated by conventional surgical drilling. This work is timely because trauma is an important consideration to clinicians and health care providers. Cochleostomy is one of the major and most disruptive surgical process during cochlear implantation. With the increasing amount of cochlear implant electrode array designs that are shorter and less intrusive, and the increasing demand of electric-acoustic stimulation via cochlear implant to better resemble the human auditory system, the approach to reduce disruption during cochleostomy drilling is highly relevant to the progression in the hearing care industry and the benefits of the growing hearing impairment community.
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Deshpande, Aniruddha K. "Functional Magnetic Resonance Imaging (fMRI) as a Pre-Implant Objective Tool to Predict Post-Implant Speech-Language-Hearing Outcomes in Children with Cochlear Implants." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1406809574.
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