Supra-threshold perception and neural representation of tones presented in noise in conditions of masking release.

Katharina Egger,Bastian Epp,Torsten Dau,Manuel S Malmierca

doi:10.1371/journal.pone.0222804

Katharina Egger, Bastian Epp + Show 2 more

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https://doi.org/10.1371/journal.pone.0222804

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Journal: PloS one	Publication Date: Oct 10, 2019
Citations: 5	License type: CC BY 4.0

Affiliation: Technical University of Denmark

Abstract

The neural representation and perceptual salience of tonal signals presented in different noise maskers were investigated. The properties of the maskers and signals were varied such that they produced different amounts of either monaural masking release, binaural masking release, or a combination of both. The signals were then presented at different levels above their corresponding masked thresholds and auditory evoked potentials (AEPs) were measured. It was found that, independent of the masking condition, the amplitude of the P2 component of the AEP was similar for the same stimulus levels above masked threshold, suggesting that both monaural and binaural effects of masking release were represented at the level of the auditory pathway where P2 is generated. The perceptual salience of the signal was evaluated at equal levels above masked threshold using a rating task. In contrast to the electrophysiological findings, the subjective ratings of the perceptual signal salience were less consistent with the signal level above masked threshold and varied strongly across listeners and masking conditions. Overall, the results from the present study suggest that the P2 amplitude of the AEP represents an objective indicator of the audibility of a target signal in the presence of complex acoustic maskers.

Highlights

One major task of the auditory system is to distinguish between different sound sources and to segregate single sources from the acoustic background
Many aspects of auditory signal detection in noise can be accounted for by the power spectrum model of masking [1]. This model assumes that the frequency selectivity of the auditory system can be represented as a bank of overlapping band-pass filters and that the detection threshold of a tonal signal in the presence of a noise masker is mainly determined by the signal-to-masker energy ratio at the output of a band-pass filter centered at the signal frequency
The present study extended the investigations of [36] and considered three experiments using a flanking-band paradigm: In the first experiment, behavioral detection thresholds of masked tonal signals were obtained in conditions reflecting either purely monaural, purely binaural, or a combination of monaural and binaural masking releases

Summary

Introduction

One major task of the auditory system is to distinguish between different sound sources and to segregate single sources from the acoustic background. The ability of the auditory system to benefit from these cues is often assessed via the effect of masking of a tonal signal by a noise masker. Many aspects of auditory signal detection in noise can be accounted for by the power spectrum model of masking [1]. This model assumes that the frequency selectivity of the auditory system can be represented as a bank of overlapping band-pass filters and that the detection threshold of a tonal signal in the presence of a noise masker is mainly determined by the signal-to-masker energy ratio at the output of a band-pass filter centered at the signal frequency.

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