Evaluation of performance of hearing aid users using Acoustic Change Complex (ACC) and behavioral measures

To validate the clinical use of Acoustic Change Complex (ACC) as an objective tool in children who use hearing Aids and explore how far ACC response parameters could be correlated to behavioral tests.

Sixty Arabic speaking children, using binaural Hearing Aids (H.As), participated in the present study. Their age ranged from 6 to 12 years. Evaluation of Hearing aid device performance was performed through questionnaire, speech in noise tests and aided/unaided ACC recordings. Two stimuli '' vowel/o/with SNR (0 &+8) ''were developed and standardized to elicit ACC response. The replicated ACC waveforms were collected and analyzed and the aided ACC responses were compared with unaided ACC and correlated to behavioral tests.

The ACC percent identification in children using H.As using vowel/o/with SNR (+8 & 0) stimuli was 75% and 45% respectively in aided condition, the percent decreased to 40% and 15% in unaided condition. Speech in noise stimuli showed significant difference of ACC-N1 latency between the aided and unaided groups being longer in the unaided condition. The correlations between behavioral tests and ACC response (latency and amplitude) were irrelevant.

Hearing-impaired subjects can process speech stimulus at the level of the auditory cortex, and in a more effective manner when they used their H.As. ACC can be used as an objective measure for selective auditory attention ability using vowel-in-noise. However, it couldn't replace Behavioral measures.