Effect of acoustic features on discrimination ability in individuals with auditory neuropathy spectrum disorder: an electrophysiological and behavioral study.

ABSTRACT

PURPOSE: The present study aimed to investigate the discrimination ability for acoustic cues in individuals with auditory neuropathy spectrum disorder (ANSD) using both behavioral and neural measures and to compare the result with normal hearing individuals. METHODS: Four naturally produced syllables /ba/, /da/, /ma/ and /pa/ were used to study discrimination skills. They were combined in pairs such that the two syllables differ in acoustic features, that is place (/ba/-/da/), manner (/ba/-/ma/) and voicing (/ba/-/pa/) cues. Thirty individuals with ANSD and 30 individuals with normal hearing sensitivity were the participants. Syllable discrimination skill was assessed using behavioral (reaction time, sensitivity and D-prime) and neural (P300) measures. RESULTS: There was prolongation in latency and reduction in amplitude of P300 in individuals with ANSD compared to individuals with normal hearing sensitivity. Individuals with ANSD showed better discrimination skill for stimulus pairs differing in the manner followed by place and the least perceived was voicing information. CONCLUSION: Discrimination ability of individuals with ANSD is found to be affected as evident on behavioral and neural measures. The discrimination ability varies with acoustic features of speech.