Amount of Frequency Compression in Bimodal Cochlear Implant Users Is a Poor Predictor for Audibility and Spatial Hearing

2021 ◽  
pp. 1-14
Author(s):  
Snandan Sharma ◽  
Waldo Nogueira ◽  
A. John van Opstal ◽  
Josef Chalupper ◽  
Lucas H. M. Mens ◽  
...  
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Sound Localization ◽  
High Frequency ◽  
Hearing Aid ◽  
Spatial Hearing ◽  
Meaningful Improvement ◽  
Frequency Compression ◽  
Knee Point ◽  
Localization Performance

Purpose Speech understanding in noise and horizontal sound localization is poor in most cochlear implant (CI) users with a hearing aid (bimodal stimulation). This study investigated the effect of static and less-extreme adaptive frequency compression in hearing aids on spatial hearing. By means of frequency compression, we aimed to restore high-frequency audibility, and thus improve sound localization and spatial speech recognition. Method Sound-detection thresholds, sound localization, and spatial speech recognition were measured in eight bimodal CI users, with and without frequency compression. We tested two compression algorithms: a static algorithm, which compressed frequencies beyond the compression knee point (160 or 480 Hz), and an adaptive algorithm, which aimed to compress only consonants leaving vowels unaffected (adaptive knee-point frequencies from 736 to 2946 Hz). Results Compression yielded a strong audibility benefit (high-frequency thresholds improved by 40 and 24 dB for static and adaptive compression, respectively), no meaningful improvement in localization performance (errors remained > 30 deg), and spatial speech recognition across all participants. Localization biases without compression (toward the hearing-aid and implant side for low- and high-frequency sounds, respectively) disappeared or reversed with compression. The audibility benefits provided to each bimodal user partially explained any individual improvements in localization performance; shifts in bias; and, for six out of eight participants, benefits in spatial speech recognition. Conclusions We speculate that limiting factors such as a persistent hearing asymmetry and mismatch in spectral overlap prevent compression in bimodal users from improving sound localization. Therefore, the benefit in spatial release from masking by compression is likely due to a shift of attention to the ear with the better signal-to-noise ratio facilitated by compression, rather than an improved spatial selectivity. Supplemental Material https://doi.org/10.23641/asha.16869485

scholarly journals Listening Effort and Speech Recognition with Frequency Compression Amplification for Children and Adults with Hearing Loss

2017 ◽  
Vol 28 (09) ◽  
pp. 823-837 ◽  
Author(s):  
Marc A. Brennan ◽  
Dawna Lewis ◽  
Ryan McCreery ◽  
Judy Kopun ◽  
Joshua M. Alexander
Keyword(s):  
Hearing Loss ◽  
Speech Recognition ◽  
High Frequency ◽  
Hearing Aid ◽  
Nonsense Word ◽  
Spectral Distortion ◽  
Listening Effort ◽  
Frequency Compression ◽  
Low Pass ◽  
Adults And Children

AbstractNonlinear frequency compression (NFC) can improve the audibility of high-frequency sounds by lowering them to a frequency where audibility is better; however, this lowering results in spectral distortion. Consequently, performance is a combination of the effects of increased access to high-frequency sounds and the detrimental effects of spectral distortion. Previous work has demonstrated positive benefits of NFC on speech recognition when NFC is set to improve audibility while minimizing distortion. However, the extent to which NFC impacts listening effort is not well understood, especially for children with sensorineural hearing loss (SNHL).To examine the impact of NFC on recognition and listening effort for speech in adults and children with SNHL.Within-subject, quasi-experimental study. Participants listened to amplified nonsense words that were (1) frequency-lowered using NFC, (2) low-pass filtered at 5 kHz to simulate the restricted bandwidth (RBW) of conventional hearing aid processing, or (3) low-pass filtered at 10 kHz to simulate extended bandwidth (EBW) amplification.Fourteen children (8–16 yr) and 14 adults (19–65 yr) with mild-to-severe SNHL.Participants listened to speech processed by a hearing aid simulator that amplified input signals to fit a prescriptive target fitting procedure.Participants were blinded to the type of processing. Participants' responses to each nonsense word were analyzed for accuracy and verbal-response time (VRT; listening effort). A multivariate analysis of variance and linear mixed model were used to determine the effect of hearing-aid signal processing on nonsense word recognition and VRT.Both children and adults identified the nonsense words and initial consonants better with EBW and NFC than with RBW. The type of processing did not affect the identification of the vowels or final consonants. There was no effect of age on recognition of the nonsense words, initial consonants, medial vowels, or final consonants. VRT did not change significantly with the type of processing or age.Both adults and children demonstrated improved speech recognition with access to the high-frequency sounds in speech. Listening effort as measured by VRT was not affected by access to high-frequency sounds.

scholarly journals The Effect of Hearing Aid Bandwidth and Configuration of Hearing Loss on Bimodal Speech Recognition in Cochlear Implant Users

2019 ◽  
Vol 40 (3) ◽  
pp. 621-635 ◽  
Author(s):  
Arlene C. Neuman ◽  
Annette Zeman ◽  
Jonathan Neukam ◽  
Binhuan Wang ◽  
Mario A. Svirsky
Keyword(s):  
Hearing Loss ◽  
Speech Recognition ◽  
Cochlear Implant ◽  
Hearing Aid

Comparing the Effect of Different Hearing Aid Fitting Methods in Bimodal Cochlear Implant Users

2019 ◽  
Vol 28 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jantien L. Vroegop ◽  
J. Gertjan Dingemanse ◽  
Marc P. van der Schroeff ◽  
André Goedegebure
Keyword(s):  
Cochlear Implant ◽  
Sound Localization ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
Speech In Noise ◽  
Localization Test ◽  
Fitting Procedures ◽  
Auditory Performance ◽  
Contralateral Ear ◽  
Noise Test

PurposeThe aim of the study was to investigate the effect of 3 hearing aid fitting procedures on provided gain of the hearing aid in bimodal cochlear implant users and their effect on bimodal benefit.MethodThis prospective study measured hearing aid gain and auditory performance in a cross-over design in which 3 hearing aid fitting methods were compared. Hearing aid fitting methods differed in initial gain prescription rule (NAL-NL2 and Audiogram+) and loudness balancing method (broadband vs. narrowband loudness balancing). Auditory functioning was evaluated by a speech-in-quiet test, a speech-in-noise test, and a sound localization test. Fourteen postlingually deafened adult bimodal cochlear implant users participated in the study.ResultsNo differences in provided gain and in bimodal performance were found for the different hearing aid fittings. For all hearing aid fittings, a bimodal benefit was found for speech in noise and sound localization.ConclusionOur results confirm that cochlear implant users with residual hearing in the contralateral ear substantially benefit from bimodal stimulation. However, on average, no differences were found between different types of fitting methods, varying in prescription rule and loudness balancing method.

Left-Right and Front-Back Spatial Hearing with Multiple Directional Microphone Configurations in Modern Hearing Aids

2014 ◽  
Vol 25 (09) ◽  
pp. 791-803 ◽  
Author(s):  
Evelyne Carette ◽  
Tim Van den Bogaert ◽  
Mark Laureyns ◽  
Jan Wouters
Keyword(s):  
Sound Localization ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Performance Measure ◽  
Frequency Dependent ◽  
Binaural Cues ◽  
Directional Microphone ◽  
Spectral Cues ◽  
Localization Performance ◽  
Asymmetric Configuration

Background: Several studies have demonstrated negative effects of directional microphone configurations on left-right and front-back (FB) sound localization. New processing schemes, such as frequency-dependent directionality and front focus with wireless ear-to-ear communication in recent, commercial hearing aids may preserve the binaural cues necessary for left-right localization and may introduce useful spectral cues necessary for FB disambiguation. Purpose: In this study, two hearing aids with different processing schemes, which were both designed to preserve the ability to localize sounds in the horizontal plane (left-right and FB), were compared. Research Design: We compared horizontal (left-right and FB) sound localization performance of hearing aid users fitted with two types of behind-the-ear (BTE) devices. The first type of BTE device had four different programs that provided (1) no directionality, (2–3) symmetric frequency-dependent directionality, and (4) an asymmetric configuration. The second pair of BTE devices was evaluated in its omnidirectional setting. This setting automatically activates a soft forward-oriented directional scheme that mimics the pinna effect. Also, wireless communication between the hearing aids was present in this configuration (5). A broadband stimulus was used as a target signal. The directional hearing abilities of the listeners were also evaluated without hearing aids as a reference. Study Sample: A total of 12 listeners with moderate to severe hearing loss participated in this study. All were experienced hearing-aid users. As a reference, 11 listeners with normal hearing participated. Data Collection and Analysis: The participants were positioned in a 13-speaker array (left-right, –90°/+90°) or 7-speaker array (FB, 0–180°) and were asked to report the number of the loudspeaker located the closest to where the sound was perceived. The root mean square error was calculated for the left-right experiment, and the percentage of FB errors was used as a FB performance measure. Results were analyzed with repeated-measures analysis of variance. Results: For the left-right localization task, no significant differences could be proven between the unaided condition and both partial directional schemes and the omnidirectional scheme. The soft forward-oriented system and the asymmetric system did show a detrimental effect compared with the unaided condition. On average, localization was worst when users used the asymmetric condition. Analysis of the results of the FB experiment showed good performance, similar to unaided, with both the partial directional systems and the asymmetric configuration. Significantly worse performance was found with the omnidirectional and the omnidirectional soft forward-oriented BTE systems compared with the other hearing-aid systems. Conclusions: Bilaterally fitted partial directional systems preserve (part of) the binaural cues necessary for left-right localization and introduce, preserve, or enhance useful spectral cues that allow FB disambiguation. Omnidirectional systems, although good for left-right localization, do not provide the user with enough spectral information for an optimal FB localization performance.

Horizontal sound localization in cochlear implant users with a contralateral hearing aid

2016 ◽  
Vol 336 ◽  
pp. 72-82 ◽  
Author(s):  
Lidwien C.E. Veugen ◽  
Maartje M.E. Hendrikse ◽  
Marc M. van Wanrooij ◽  
Martijn J.H. Agterberg ◽  
Josef Chalupper ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Sound Localization ◽  
Hearing Aid

scholarly journals Reducing the Device Delay Mismatch Can Improve Sound Localization in Bimodal Cochlear Implant/Hearing-Aid Users

2019 ◽  
Vol 23 ◽  
pp. 233121651984387 ◽  
Author(s):  
Stefan Zirn ◽  
Julian Angermeier ◽  
Susan Arndt ◽  
Antje Aschendorff ◽  
Thomas Wesarg
Keyword(s):  
Cochlear Implant ◽  
Sound Localization ◽  
Delay Line ◽  
Hearing Aid ◽  
Interaural Time Differences ◽  
Localization Accuracy ◽  
Everyday Situation ◽  
Acclimatization Period ◽  
Study Participants ◽  
Line P

In users of a cochlear implant (CI) together with a contralateral hearing aid (HA), so-called bimodal listeners, differences in processing latencies between digital HA and CI up to 9 ms constantly superimpose interaural time differences. In the present study, the effect of this device delay mismatch on sound localization accuracy was investigated. For this purpose, localization accuracy in the frontal horizontal plane was measured with the original and minimized device delay mismatch. The reduction was achieved by delaying the CI stimulation according to the delay of the individually worn HA. For this, a portable, programmable, battery-powered delay line based on a ring buffer running on a microcontroller was designed and assembled. After an acclimatization period to the delayed CI stimulation of 1 hr, the nine bimodal study participants showed a highly significant improvement in localization accuracy of 11.6% compared with the everyday situation without the delay line ( p < .01). Concluding, delaying CI stimulation to minimize the device delay mismatch seems to be a promising method to increase sound localization accuracy in bimodal listeners.

scholarly journals Recognition and Localization of Speech by Adult Cochlear Implant Recipients Wearing a Digital Hearing Aid in the Nonimplanted Ear (Bimodal Hearing)

2009 ◽  
Vol 20 (06) ◽  
pp. 353-373 ◽  
Author(s):  
Lisa G. Potts ◽  
Margaret W. Skinner ◽  
Ruth A. Litovsky ◽  
Michael J. Strube ◽  
Francis Kuk
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Repeated Measures ◽  
Dynamic Range ◽  
Hearing Aid ◽  
Bilateral Stimulation ◽  
Bimodal Condition ◽  
Digital Hearing Aid ◽  
Loudness Growth ◽  
Bimodal Hearing

Background: The use of bilateral amplification is now common clinical practice for hearing aid users but not for cochlear implant recipients. In the past, most cochlear implant recipients were implanted in one ear and wore only a monaural cochlear implant processor. There has been recent interest in benefits arising from bilateral stimulation that may be present for cochlear implant recipients. One option for bilateral stimulation is the use of a cochlear implant in one ear and a hearing aid in the opposite nonimplanted ear (bimodal hearing). Purpose: This study evaluated the effect of wearing a cochlear implant in one ear and a digital hearing aid in the opposite ear on speech recognition and localization. Research Design: A repeated-measures correlational study was completed. Study Sample: Nineteen adult Cochlear Nucleus 24 implant recipients participated in the study. Intervention: The participants were fit with a Widex Senso Vita 38 hearing aid to achieve maximum audibility and comfort within their dynamic range. Data Collection and Analysis: Soundfield thresholds, loudness growth, speech recognition, localization, and subjective questionnaires were obtained six–eight weeks after the hearing aid fitting. Testing was completed in three conditions: hearing aid only, cochlear implant only, and cochlear implant and hearing aid (bimodal). All tests were repeated four weeks after the first test session. Repeated-measures analysis of variance was used to analyze the data. Significant effects were further examined using pairwise comparison of means or in the case of continuous moderators, regression analyses. The speech-recognition and localization tasks were unique, in that a speech stimulus presented from a variety of roaming azimuths (140 degree loudspeaker array) was used. Results: Performance in the bimodal condition was significantly better for speech recognition and localization compared to the cochlear implant–only and hearing aid–only conditions. Performance was also different between these conditions when the location (i.e., side of the loudspeaker array that presented the word) was analyzed. In the bimodal condition, the speech-recognition and localization tasks were equal regardless of which side of the loudspeaker array presented the word, while performance was significantly poorer for the monaural conditions (hearing aid only and cochlear implant only) when the words were presented on the side with no stimulation. Binaural loudness summation of 1–3 dB was seen in soundfield thresholds and loudness growth in the bimodal condition. Measures of the audibility of sound with the hearing aid, including unaided thresholds, soundfield thresholds, and the Speech Intelligibility Index, were significant moderators of speech recognition and localization. Based on the questionnaire responses, participants showed a strong preference for bimodal stimulation. Conclusions: These findings suggest that a well-fit digital hearing aid worn in conjunction with a cochlear implant is beneficial to speech recognition and localization. The dynamic test procedures used in this study illustrate the importance of bilateral hearing for locating, identifying, and switching attention between multiple speakers. It is recommended that unilateral cochlear implant recipients, with measurable unaided hearing thresholds, be fit with a hearing aid.

scholarly journals Self-Reported Spatial Hearing Abilities Across Different Cochlear Implant Profiles

2014 ◽  
Vol 23 (4) ◽  
pp. 374-384 ◽  
Author(s):  
Ann E. Perreau ◽  
Hua Ou ◽  
Richard Tyler ◽  
Camille Dunn
Keyword(s):  
Retrospective Study ◽  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Hearing Aid ◽  
Spatial Hearing ◽  
Separate Analysis ◽  
Hearing Ability ◽  
Significant Difference ◽  
Hearing Abilities

Purpose The goal of this study was to determine how self-reported spatial hearing abilities differ across various cochlear implant (CI) profiles and to examine the degree of subjective benefit following cochlear implantation across different groups of CI users. Method This was a retrospective study of subjective spatial hearing ability of CI recipients. The subjects consisted of 99 unilateral CI users, 49 bilateral CI users, 32 subjects with a CI and contralateral hearing aid (bimodal users), and 37 short-electrode CI users. All subjects completed the Spatial Hearing Questionnaire (Tyler, Perreau, & Ji, 2009), a questionnaire assessing spatial hearing ability, after implantation, and a subset of the subjects completed the questionnaire pre- and postimplantation. Results Subjective spatial hearing ability was rated higher for the bilateral and short electrode CI users compared to the unilateral and bimodal users. There was no significant difference in subjective spatial hearing performance between the bilateral and short electrode CI users and the unilateral CI and bimodal users. A separate analysis of pre- and postimplant performance revealed that all CI groups reported significant improvements in spatial hearing ability after implantation. Conclusion This study suggests that there are substantial differences in perceived spatial hearing ability among unilateral and bimodal CI users compared with bilateral and short electrode CI users.

scholarly journals Sound Localization in Single-Sided Deaf Participants Provided With a Cochlear Implant

2021 ◽  
Vol 12 ◽  
Author(s):  
Alexandra Annemarie Ludwig ◽  
Sylvia Meuret ◽  
Rolf-Dieter Battmer ◽  
Marc Schönwiesner ◽  
Michael Fuchs ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Sound Localization ◽  
High Frequency ◽  
Real Life ◽  
Low Frequency ◽  
Normal Hearing ◽  
Frequency Noise ◽  
Speech Understanding ◽  
Speech Understanding In Noise ◽  
Single Sided Deafness

Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This ability can potentially be improved with a unilateral cochlear implant (CI). The present study investigated measures of sound localization in participants with single-sided deafness provided with a CI. Sound localization was measured separately at eight loudspeaker positions (4°, 30°, 60°, and 90°) on the CI side and on the normal-hearing side. Low- and high-frequency noise bursts were used in the tests to investigate possible differences in the processing of interaural time and level differences. Data were compared to normal-hearing adults aged between 20 and 83. In addition, the benefit of the CI in speech understanding in noise was compared to the localization ability. Fifteen out of 18 participants were able to localize signals on the CI side and on the normal-hearing side, although performance was highly variable across participants. Three participants always pointed to the normal-hearing side, irrespective of the location of the signal. The comparison with control data showed that participants had particular difficulties localizing sounds at frontal locations and on the CI side. In contrast to most previous results, participants were able to localize low-frequency signals, although they localized high-frequency signals more accurately. Speech understanding in noise was better with the CI compared to testing without CI, but only at a position where the CI also improved sound localization. Our data suggest that a CI can, to a large extent, restore localization in participants with single-sided deafness. Difficulties may remain at frontal locations and on the CI side. However, speech understanding in noise improves when wearing the CI. The treatment with a CI in these participants might provide real-world benefits, such as improved orientation in traffic and speech understanding in difficult listening situations.

scholarly journals Transitioning From Bimodal to Bilateral Cochlear Implant Listening: Speech Recognition and Localization in Four Individuals

2014 ◽  
Vol 23 (1) ◽  
pp. 79-92 ◽  
Author(s):  
Lisa G. Potts ◽  
Ruth Y. Litovsky
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Hearing Aid ◽  
Strong Preference ◽  
Bilateral Stimulation ◽  
Test Procedures ◽  
Performance Differences ◽  
Bilateral Cochlear Implant ◽  
Better Than ◽  
Bimodal Hearing

Purpose The use of bilateral stimulation is becoming common for cochlear implant (CI) recipients with either (a) a CI in one ear and a hearing aid (HA) in the nonimplanted ear (CI&HA—bimodal) or (b) CIs in both ears (CI&CI—bilateral). The objective of this study was to evaluate 4 individuals who transitioned from bimodal to bilateral stimulation. Method Participants had completed a larger study of bimodal hearing and subsequently received a second CI. Test procedures from the bimodal study, including roaming speech recognition, localization, and a questionnaire (the Speech, Spatial, and Qualities of Hearing Scale; Gatehouse & Noble, 2004) were repeated after 6–7 months of bilateral CI experience. Results Speech recognition and localization were not significantly different between bimodal and unilateral CI. In contrast, performance was significantly better with CI&CI compared with unilateral CI. Speech recognition with CI&CI was significantly better than with CI&HA for 2 of 4 participants. Localization was significantly better for all participants with CI&CI compared with CI&HA. CI&CI performance was rated as significantly better on the Speech, Spatial, and Qualities of Hearing Scale compared with CI&HA. Conclusions There was a strong preference for CI&CI for all participants. The variability in speech recognition and localization, however, suggests that performance under these stimulus conditions is individualized. Differences in hearing and/or HA history may explain performance differences.

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