Effects of spatial separation with better- ear listening on N1-P2 complex

Abstract

Objective: The purpose of this study was to determine better- ear listening effect on spatial separation with the N1-P2 complex.

Methods: Twenty individuals with normal hearing participated in this study. The speech stimulus /ba/ was presented in front of the participant (0°). Continuous Speech Noise (5 dB signal-to-noise ratio) was presented either in front of the participant (0°), left-side (-90°), or right-side (+90°). N1- P2 complex has been recorded in quiet and three noisy conditions.

Results: There was a remarkable effect of noise direction on N1, P2 latencies. When the noise was separated from the stimulus, N1 and P2 latency increased in terms of when noise was co-located with the stimulus. There was no statistically significant difference in N1-P2 amplitudes between the stimulus-only and co-located condition. N1-P2 amplitude was increased when the noise came from the sides, according to the stimulus-only and co-located conditions.

Conclusion: These findings demonstrate that the latency shifts on N1-P2 complex explain cortical mechanisms of spatial separation in better-ear listening.

Keywords: Better-ear listening; Head-shadow effect; N1-P2 complex; Spatial release from masking; Spatial separation.