Brainstem Encoding of Aided Speech in Hearing Aid Users with Cochlear Dead Region(s)

Speech auditory brainstem response in audiological practice: a systematic review

BACKGROUND

Speech-ABR is an auditory brainstem response that evaluates the integrity of the temporal and spectral coding of speech in the upper levels of the brainstem. It reflects the acoustic properties of the stimulus used and consists of seven major waves. Waves V and A represent the onset of the response; wave C transition region; D, E, and F waves periodic region (frequency following response); and wave O reflects the offset of the response.

PURPOSE

The aim of this study is to evaluate the clinical availability of the speech-ABR procedure through a literature review.

METHODS

Literature search was conducted in Pubmed, Google Scholar, Scopus and Science Direct databases. Clinical studies of the last 15 years have been included in this review and 60 articles have been reviewed.

RESULTS

As a result of the articles reviewed, it was seen that most of the studies on speech ABR were conducted with children and young people and generally focused on latency analysis measurements. Most used stimulus is the /da/ syllable.

CONCLUSIONS

Speech ABR can objectively measure the auditory cues important for speech recognition and has many clinical applications. It can be used as a biomarker for auditory processing disorders, learning disorders, dyslexia, otitis media, hearing loss, language disorders and phonological disorders. S-ABR is an effective procedure that can be used in speech and language evaluations in people with hearing aids or cochlear implant. It may also be of benefit to the aging auditory system's ability to encode temporal cues.

Systematic review of cochlear implantation in adults with asymmetrical hearing loss

BACKGROUND

Rapid advances in cochlear implantation has witnessed an expanding spectrum for candidacy worldwide. This includes a subgroup of adults with asymmetrical hearing loss who have a wide range in their hearing capacity between the two ears. As per guidelines they are not included in mainstream candidacy for CI across the world. Evidence is now emerging to support the benefits of CI in AHL.

METHODS

This review analyzed literature regarding the outcomes of CI in AHL. Primary outcome measure was to assess audiological benefits and secondary outcome measure was to assess hearing related quality of life. 15 relevant articles, published worldwide between 2009 and 2019 were chosen. CASP checklist for systematic reviews was used to ascertain the quality of literature. The strength of recommendations from each study was analyzed and classified as strong, moderate, weak or none based on GRADE guidelines.

RESULTS

Heterogeneity in samples was obvious and samples varied largely between the studies. The levels of evidence ranged from systematic review to expert opinion, but overall they reflected positively on both audiological and QOL benefits.

CONCLUSION

CI provides important auditory and QOL benefits in AHL, but there is no high level evidence as yet to strongly support CI for AHL. A long term multi-centric study is necessary to influence a change in practice for a growing population of AHL.Trial registration: ClinicalTrials.gov identifier: NCT03052920.