Comparisons of auditory cortical imaging for the various dichotic listening

Abstract

Aim: The study was designed to estimate the auditory laterality of the human brain that was based on the dichotic listening (DL) technique. Non-invasive detection to know the ear advantage is useful for the hearing aid fitting for mono-aural wearing. Subject: Ten normal hearing adult volunteers were employed in this study. Methods: 31ch-Auditory-evoked potentials (AEP) for the dichotic sounds were recorded electrically from the scalp. A 60dBSPL of vowel “/a/” was represented mono-aurally with a 50dBSPL of the contra-lateral masking noise, white noise, and multi-talker noise. Brain functions, especially for the cortical response, within the dichotic listening were visualized non-invasively using the scalp potential-based Laplacian mapping technique. Results: Right ear advantage for vowel sound within the left-brain dominancy can be observed in six subjects. The remaining four subjects could not be categorized in the term of ear advantage or brain laterality. Conclusion: It is observed that the auditory processing for the dichotic listening behavior differed from the mono-aural listening. Objective and non-invasive assessment for the brain laterality within the auditory dominancy can be applied for the hearing aids fitting technique.