scholarly journals A Literature Review of Bimodal Fitting

2020 ◽  
Vol 16 (4) ◽  
pp. 265-275
Author(s):  
Junghwa Bahng ◽  
Soo Hee Oh
Keyword(s):  
Cochlear Implant ◽  
Frequency Band ◽  
Hearing Aid ◽  
Low Frequency ◽  
Balance Test ◽  
Band Frequency ◽  
Hearing Aid Fitting ◽  
Fitting Procedures ◽  
Band Adjustment ◽  
Bimodal Hearing

Although there are quite a few bimodal cochlear implant users, bimodal fitting guidelines were not fully developed. Bimodal fitting optimization is one of the factors that contribute to successful bimodal outcomes. The purpose of this study is to investigate recent literatures related to bimodal fitting to establish evidence based bimodal fitting guidelines. Three databases including Google Scholar, PubMed publisher, and PLOS One were searched to review bimodal fitting literatures. A total of 599,604 articles were identified by using ten bimodal relevant keywords at the initial stage. Then, we included 192 articles with abstract review, inclusion and exclusion criteria and removals of duplicates. Lastly, two authors reviewed full texts and identified a total of 19 bimodal fitting articles. Results were categorized into type of bimodal intervention, procedures, and outcomes. Bimodal fitting procedures, test materials, and questionnaires were also summarized. A total of 18 articles consist of bimodal hearing aid fitting covering hearing aid fitting formula, gain adjustment, loudness balance, frequency band, frequency lowering technology, and overall bimodal fitting guidelines. Only one article includes bimodal cochlear implant fitting with low frequency band adjustment. Several factors including real-ear measurement, loudness balance test, frequency band selection considering cochlear dead region, and subjective questionnaires are considered to optimize bimodal hearing aid fitting. Bimodal fitting guidelines considering several relevant factors will optimize bimodal fitting and improve bimodal benefits.

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.

scholarly journals Effects of Removing Low-Frequency Electric Information on Speech Perception With Bimodal Hearing

2016 ◽  
Vol 59 (1) ◽  
pp. 99-109 ◽  
Author(s):  
Jennifer R. Fowler ◽  
Jessica L. Eggleston ◽  
Kelly M. Reavis ◽  
Garnett P. McMillan ◽  
Lina A. J. Reiss
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Hearing Aid ◽  
Cutoff Frequency ◽  
Low Frequency ◽  
Improve Performance ◽  
Frequency Information ◽  
Bimodal Condition ◽  
Contralateral Ear ◽  
Bimodal Hearing

PurposeThe objective was to determine whether speech perception could be improved for bimodal listeners (those using a cochlear implant [CI] in one ear and hearing aid in the contralateral ear) by removing low-frequency information provided by the CI, thereby reducing acoustic–electric overlap.MethodSubjects were adult CI subjects with at least 1 year of CI experience. Nine subjects were evaluated in the CI-only condition (control condition), and 26 subjects were evaluated in the bimodal condition. CIs were programmed with 4 experimental programs in which the low cutoff frequency (LCF) was progressively raised. Speech perception was evaluated using Consonant-Nucleus-Consonant words in quiet, AzBio sentences in background babble, and spondee words in background babble.ResultsThe CI-only group showed decreased speech perception in both quiet and noise as the LCF was raised. Bimodal subjects with better hearing in the hearing aid ear (< 60 dB HL at 250 and 500 Hz) performed best for words in quiet as the LCF was raised. In contrast, bimodal subjects with worse hearing (> 60 dB HL at 250 and 500 Hz) performed similarly to the CI-only group.ConclusionsThese findings suggest that reducing low-frequency overlap of the CI and contralateral hearing aid may improve performance in quiet for some bimodal listeners with better hearing.

scholarly journals When to provide bimodal stimulation in unilateral cochlear implant recepients

2016 ◽  
Vol 3 (1) ◽  
pp. 128
Author(s):  
Poonam Raj ◽  
Ruchika Mittal
Keyword(s):  
Cochlear Implant ◽  
Hearing Aid ◽  
Noisy Environment ◽  
Implant Surgery ◽  
Maximum Benefit ◽  
Cochlear Implant Surgery ◽  
Group 2 ◽  
Achieve Maximum Benefit ◽  
Group 1 ◽  
Bimodal Hearing

<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>

scholarly journals A Study on the Preferred Real-Ear Insertion Gain of Multi-Channel Hearing Aid for the Korean with Sensorineural Hearing Loss

2020 ◽  
Vol 16 (2) ◽  
pp. 85-94
Author(s):  
Eojini Bang ◽  
Kyoungwon Lee
Keyword(s):  
Word Recognition ◽  
Hearing Aids ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
High Frequencies ◽  
Frequency Bands ◽  
Before And After ◽  
Fitting Procedures ◽  
Linear Version ◽  
Gain Adjustment

Purpose: This study aimed to compare the preferred real-ear insertion gain for Korean (PREIG-K) wearing multi-channel hearing aid with the National Acoustics Laboratories-Non-Linear version 2 (NAL-NL2; National Acoustic Laboratories) gains in order to develop Korean hearing aid fitting formula.Methods: A total of thirty one (62 ears) Korean hearing aid users were included in this study. All subjects wore in-the-canal or custom hearing aids in both ears. Individual hearing aid fitting procedures involved to adjust the gains for 50, 65, and 80 dB sound pressure level of speech across low, high, and wideband frequency bands based on participant’s subjective responses. In addition, only the high frequency bands of 1 kHz or more of the PREIG-K were re-adjusted to be the same as NAL-NL2 gain and then the word recognition scores (WRSs) were compared before and after the adjusting gain. Results: The results showed that the PREIG-K increased up to 1.5 kHz with the maximum amount, then the PREIG-K decreased across the frequencies. For all half octave frequencies, the PREIG-Ks were substantially less than the NAL-NL2. When the PREIG-K of high frequencies were re-adjusted same as the NAL-NL2 gains, the WRSs of the PREIG-K were not significantly different before and after gain adjustment. The slopes up to 1.5 kHz frequencies of the PREIG-K were steeper than the slopes of NAL-NL2 gain, however similar to the slope of manufactures’ fitting formulae.Conclusion: The development of an effective hearing aid fitting formula for improving the communication abilities of hearing-impaired Korean will require further experiments considering the language, physical characteristics, and word recognition used by Koreans.

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 A review of hearing aid fitting procedures

2017 ◽  
Vol 60 (4) ◽  
pp. 201-209 ◽  
Author(s):  
Hajime Sano
Keyword(s):  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
Fitting Procedures

Experimental Study of Jet Noise Characteristics of Series Connected Nozzles

2005 ◽  
Author(s):  
Qiang Xu
Keyword(s):  
Frequency Spectrum ◽  
Frequency Band ◽  
Low Frequency ◽  
Jet Noise ◽  
Steel Tube ◽  
The Other ◽  
Chamber Pressure ◽  
Band Frequency ◽  
Noise Characteristics ◽  
Frequency Peak

Put abstract text here. A serial of experiments were conducted to study the noise radiated from a series connected nozzle pair. The experiment results are presented in this paper. This nozzle pair consists of two nozzles, one is called source nozzle, and the other is a secondary nozzle. In these experiments, the structure of source nozzle was fixed while that of secondary nozzle was changeable. The source nozzle is mounted on a pressure chamber which is connected to an air compressor. A steel tube is fixed at the tail of source nozzle. The secondary nozzle is connected to the other end of the tube. Throat size of secondary nozzle is larger then that of source nozzle. 15 types of nozzles with different expansion ratio, length of expand segment, and throat structure were used as the secondary nozzle. Jet noise pressure of these nozzle pairs was measured by 40AF Free Field Microphone. The frequency spectrum of jet noise from source nozzle with steel tube under different chamber pressures was calculated. The pressure range is from 0.1 to 1.2 MPa. This result is compared with those spectrums of nozzle pair with different secondary nozzle under different chamber pressures. The trend of peak frequency shifts for different nozzle pair and different chamber pressure is presented in this paper. The secondary nozzles make frequency peak shift from the source nozzle, especially in low frequency band. Different structure of secondary nozzle has different influence on the frequency characteristics of jet noise. Length of expand segment has greater influence on low frequency peak than other two factors. Joint time-frequency analysis is also used in analyze the change of frequency spectrum during throat size decreased under fixed chamber pressure and various spectrograms are also presented. In low frequency band, frequency peak remains during the change of source nozzle throat size. But in higher frequency band, the frequency peak shifts from low frequency to higher ones as the throat size decreases.

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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