Bimodal Hearing Aid Research Articles

Case Reports of Hearing Aid Fitting in Bimodal Cochlear Implant Adults

The purpose of this case study is to investigate the bimodal benefits and clinical applications of bimodal hearing aid fitting. Bimodal hearing aid fitting was conducted with four bimodal cochlear implant adults. In order to evaluate bimodal benefits, speech recognition tests in quiet and noise conditions and “Speech, Spatial and Qualities of Hearing Scale (SSQ)” questionnaire were performed before and 1 month after bimodal hearing aid fitting. Four cases showed critical improvements in speech recognition tests and SSQ questionnaire scores. Four bimodal users showed improvement in speech perception and SSQ questionnaire after bimodal fitting. Clinical application of bimodal hearing aid fitting will be necessary to improve bimodal benefits and maintain good audibility of the contralateral ear of bimodal users.

Guidelines for Best Practice in the Audiological Management of Adults Using Bimodal Hearing Configurations.

Clinics are treating a growing number of patients with greater amounts of residual hearing. These patients often benefit from a bimodal hearing configuration in which acoustic input from a hearing aid on 1 ear is combined with electrical stimulation from a cochlear implant on the other ear. The current guidelines aim to review the literature and provide best practice recommendations for the evaluation and treatment of individuals with bilateral sensorineural hearing loss who may benefit from bimodal hearing configurations. Specifically, the guidelines review: benefits of bimodal listening, preoperative and postoperative cochlear implant evaluation and programming, bimodal hearing aid fitting, contralateral routing of signal considerations, bimodal treatment for tinnitus, and aural rehabilitation recommendations.

A Retrospective Study of Bimodal Benefits of Cochlear Implant Children

Purpose: Bimodal children showed various improvements in speech, language, and music perception. The purpose of this study is to investigate bimodal benefits and bimodal hearing aid fitting of cochlear implant children with a retrospective chart review.Methods: A total of 44 charts of cochlear implant children were retrospectively reviewed in this study. Hearing thresholds, word recognition scores, and hearing aid fitting procedures were reviewed and summarized.Results: Bimodal children showed 4%points improvements in word recognition scores and 30~40 gains across frequencies with hearing aids. For bimodal hearing aid fitting, all children used desired sensation level v5 fitting formula with wide frequency bands. Real ear measurements were performed to match with targets and loudness balancing across ears was also conducted. Hearing thresholds with and without hearing aids were not correlated with word recognition scores in bimodal condition.Conclusion: Bimodal children showed improved hearing thresholds with hearing aids and little bimodal benefits in word recognition tests. Additional protocols including speech in noise tests, subjective questionnaires are recommended to evaluate bimodal benefits.

Speech and Sound Quality Recognition in Adults Bimodal Cochlear Implant Listeners

Purpose: Recent bimodal studies identified a lack of bimodal evaluation and fitting protocols to improve bimodal benefits. The purpose of this study is to measure bimodal benefits in speech and sound quality recognition and identify bimodal fitting issues with adult cochlear implant listeners to establish bimodal fitting guidelines and evaluation protocol.Methods: A total of 20 adult cochlear implant users were participated in this study. The experimental procedures included basic evaluation, hearing aid evaluation, and bimodal benefits evaluation. In order to evaluate bimodal benefits, speech and sound quality recognition tests were performed. Matrix sentences in quiet and noise (5 and 10 dB sound pressure level), consonant-vowel-consonant words, and story comprehension tasks were provided. Participants judged sound qualities for six sound quality dimensions and a tester performed real ear measurements to verify hearing aid gains.Results: Results showed that bimodal listeners had some bimodal benefits in the sentence and monosyllabic word recognition in quiet. The benefits of sound quality judgments were also observed for six sound quality dimensions. Bimodal cochlear implant listeners of this study demonstrated less real-ear insertion gains than target gains across test frequencies.Conclusion: Speech and sound quality recognition tests are useful tools to measure bimodal benefits. Additional care for bimodal listeners is needed to optimize bimodal fitting and improve the quality of bimodal hearing aid fitting services.

Self-assessment of unilateral and bimodal cochlear implant experiences in daily life.

The subjective experiences were assessed of cochlear implant (CI) users either wearing or not wearing a hearing aid (HA) at the contralateral ear. Unilateral CI-recipients were asked to fill out a set of daily-life questionnaires on bimodal HA use, hearing disability, hearing handicap and general quality of life. Twenty-six CI-recipients who regularly use a contralateral HA (bimodal group) and twenty-two CI-recipients who do not use a HA in the contralateral ear (unilateral group). Comparisons between both groups (bimodal versus unilateral) showed no difference in self-rated disability, hearing handicap or general quality of life. However within the group of bimodal listeners, participants did report a benefit of bimodal hearing ability in various daily life listening situations. Bimodal benefit in daily life can consistently be experienced and reported within the group of bimodal users.

A Literature Review of Bimodal Fitting

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.

A Review of Bimodal Hearing Aid Fitting

A Review of Bimodal Hearing Aid Fitting

Bimodal Hearing Aid Retention after Unilateral Cochlear Implantation

The goal of this study was to investigate contralateral hearing aid (HA) use after unilateral cochlear implantation and to identify factors of influence on the occurrence of a unilateral cochlear implant (CI) recipient becoming a bimodal user. A retrospective cross-sectional chart review was carried out among 77 adult unilateral CI recipients 1 year after implantation. A bimodal HA retention rate of 64% was observed. Associations with demographics, hearing history, residual hearing and speech recognition ability were investigated. Better pure-tone thresholds and unaided speech scores in the non-implanted ear, as well as a smaller difference in speech recognition scores between both ears, were significantly associated with HA retention. A combined model of HA retention was proposed, and cut-off points were determined to identify those CI recipients who were most likely to become bimodal users. These results can provide input to clinical guidelines concerning bimodal CI candidacy.