Auditory Sensory Gating of Speech and Nonspeech Stimuli

Abstract

Purpose Auditory sensory gating is a neural measure of inhibition and is typically measured with a click or tonal stimulus. This electrophysiological study examined if stimulus characteristics and the use of speech stimuli affected auditory sensory gating indices. Method Auditory event-related potentials were elicited using natural speech, synthetic speech, and nonspeech stimuli in a traditional auditory gating paradigm in 15 adult listeners with normal hearing. Cortical responses were recorded at 64 electrode sites, and peak amplitudes and latencies to the different stimuli were extracted. Individual data were analyzed using repeated-measures analysis of variance. Results Significant gating of P1–N1–P2 peaks was observed for all stimulus types. N1–P2 cortical responses were affected by stimulus type, with significantly less neural inhibition of the P2 response observed for natural speech compared to nonspeech and synthetic speech. Conclusions Auditory sensory gating responses can be measured using speech and nonspeech stimuli in listeners with normal hearing. The results of the study indicate the amount of gating and neural inhibition observed is affected by the spectrotemporal characteristics of the stimuli used to evoke the neural responses.