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

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.

2009 ◽  
Vol 20 (06) ◽  
pp. 353-373 ◽  
Author(s):  
Lisa G. Potts ◽  
Margaret W. Skinner ◽  
Ruth A. Litovsky ◽  
Michael J. Strube ◽  
Francis Kuk

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.


2019 ◽  
Vol 40 (3) ◽  
pp. 621-635 ◽  
Author(s):  
Arlene C. Neuman ◽  
Annette Zeman ◽  
Jonathan Neukam ◽  
Binhuan Wang ◽  
Mario A. Svirsky

Author(s):  
Poonam Raj ◽  
Ruchika Mittal

<p class="abstract"><strong>Background:</strong> With the steady increase in unilateral cochlear implant surgery as management of bilateral sensorineural hearing loss, the benefits of bimodal hearing have been well documented. However very few studies are available on the timing of bimodal hearing stimulation after cochlear implantation. The present study deals with when to provide bimodal hearing in unilaterally implanted children to achieve maximum benefit<span lang="EN-IN">. </span></p><p class="abstract"><strong>Methods:</strong> This study was carried out in 120 children aged between 3-5 years who underwent unilateral cochlear implant surgery. The implant was switched-on two weeks after surgery in all cases. The children were randomized into two groups of 60 each. Group 1 comprised of children who continued to use hearing aid in the non-implanted ear immediately after the cochlear implant surgery. Group 2 children discontinued using hearing aid in the non-implanted ear after surgery and restarted its usage after four weeks of switch on of the cochlear implant. The progress in both groups was monitored using category of auditory performance (CAP) scores and through a questionnaire<span lang="EN-IN">.  </span></p><p class="abstract"><strong>Results:</strong> The mean age of the children was 3.55 years. 11.6 % of the recipients could localize sounds and 5% could understand speech in noisy environment in Group 2 whereas in 1.7% of the recipients could localize sounds and none of the recipient could understand speech in noisy environment in Group 1 after 3 months of follow up.  CAP scores increased steadily in Group 2 over the study period whereas Group 1 recipients did not show the same progress<span lang="EN-IN">. </span></p><p class="abstract"><strong>Conclusions:</strong> We recommend that bimodal fitting should be the standard practice for clinical management of children who receive unilateral cochlear implant. The best practice is to restart the use of the hearing aid in the non-implanted ear, after one month of activation of the implant to achieve maximum benefit<span lang="EN-IN">.</span></p>


Author(s):  
Snandan Sharma ◽  
Waldo Nogueira ◽  
A. John van Opstal ◽  
Josef Chalupper ◽  
Lucas H. M. Mens ◽  
...  

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


2003 ◽  
Vol 14 (02) ◽  
pp. 084-099 ◽  
Author(s):  
Francis K. Kuk ◽  
Lisa Potts ◽  
Michael Valente ◽  
Lidia Lee ◽  
Jay Picirrillo

The present study examined the phenomenon of acclimatization in persons with a severe-to-profound hearing loss. A secondary purpose was to examine the efficacy of a digital nonlinear power hearing aid that has a low compression threshold with expansion for this population. Twenty experienced hearing aid users wore the study hearing aids for three months and their performance with the study hearing aids was evaluated at the initial fitting, one month, and three months after the initial fitting. Performance of their current hearing aids was also evaluated at the initial fitting. Speech recognition testing was conducted at input levels of 50 dB SPL and 65 dB SPL in quiet, and 75 dB SPL in noise at a +10 SNR. Questionnaires were used to measure subjective performance at each evaluation interval. The results showed improvement in speech recognition score at the one-month evaluation over the initial evaluation. No significant improvement was seen at the three-month evaluation from the one-month visit. In addition, subjective and objective performance of the study hearing aids was significantly better than the participants' own hearing aids at all evaluation intervals. These results provided evidence of acclimatization in persons with a severe-to-profound hearing loss and reinforced the precaution that any trial of amplification, especially from linear to nonlinear mode, should consider this phenomenon.


2006 ◽  
Vol 27 (6) ◽  
pp. 763-773 ◽  
Author(s):  
Todd A. Ricketts ◽  
D Wesley Grantham ◽  
Daniel H. Ashmead ◽  
David S. Haynes ◽  
Robert F. Labadie

2020 ◽  
Vol 63 (6) ◽  
pp. 1712-1725
Author(s):  
Xin Luo ◽  
Courtney Kolberg ◽  
Kathryn R. Pulling ◽  
Tamiko Azuma

Purpose This study aimed to evaluate the effects of aging and cochlear implant (CI) on psychoacoustic and speech recognition abilities and to assess the relative contributions of psychoacoustic and demographic factors to speech recognition of older CI (OCI) users. Method Twelve OCI users, 12 older acoustic-hearing (OAH) listeners age-matched to OCI users, and 12 younger normal-hearing (YNH) listeners underwent tests of temporal amplitude modulation detection, temporal gap detection in noise, and spectral–temporal modulated ripple discrimination. Speech reception thresholds were measured for sentence recognition in multitalker, speech-babble noise. Results Statistical analyses showed that, for the small sample of OAH listeners, the degree of hearing loss did not significantly affect any outcome measure. Temporal resolution, spectral resolution, and speech recognition all significantly degraded with both age and the use of a CI (i.e., YNH better than OAH and OAH better than OCI performance). Although both were significantly correlated with OCI users' speech recognition, the duration of CI use no longer had a significant effect on speech recognition once the effect of spectral–temporal ripple discrimination performance was taken into account. For OAH listeners, the only significant predictor of speech recognition was temporal gap detection performance. Conclusion The preliminary results suggest that speech recognition of OCI users may improve with longer duration of CI use, mainly due to higher perceptual acuity to spectral–temporal modulated ripples in acoustic stimuli.


2018 ◽  
Vol 39 (04) ◽  
pp. 405-413 ◽  
Author(s):  
M. Dunbar ◽  
Sarah Warren

AbstractBinaural hearing offers numerous advantages over monaural hearing. While bilateral implants are a successful treatment option for some patients, many individuals choose to achieve binaural hearing by using a cochlear implant with a contralateral hearing aid. Compared with monaural hearing, benefits of bimodal hearing include improved speech perception in quiet and in noise, improved localization, and more natural sound quality. Despite the advantages, there exist disadvantages to bimodal hearing, primarily related to binaural integration. Management of these devices can be challenging in that the hearing aid and cochlear implant may be managed by different clinicians. When fitting devices, strategies are recommended to optimize the integration of input from both devices. In managing bimodal devices, recommended outcomes measures include those that would reflect bimodal benefit, such as speech understanding in noise and spatial sound quality perception.


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