Acoustic Change Complex: Neural Correlate of Speech in Noise Perception

Abstract

This study investigated the potential of an electrophysiological measure, Acoustic Change Complex (ACC) in detecting the deficits in neural encoding of speech in the presence of noise and it also aimed to identify the neural factors (latencies and amplitudes) that determine good or poor speech perception in noise. Thirty typically developing children, between 12 to l5 years participated in the study. They were divided into two groups based on behavioural speech in noise (SIN) scores as, group I (good scores) and group II (poor scores). Latency measures and peak to peak amplitude measures were obtained from ACC recordings for stimulus CV syllable /si/ in quiet and noise conditions of stimulus presentation. Results revealed significant differences between groups irrespective of the conditions and also between conditions irrespective of the groups. A significant correlation was observed between behavioural measure (SIN scores) and electrophysiological measures (latencies & amplitudes). These findings show the feasibility of using cortical responses in understanding individual's difficulty in perceiving speech in noisy background. Both latency and amplitude measures were found to depict speech perception capabilities.