Adaptation of the human auditory cortex to changing background noise

Bahar Khalighinejad,Jose L Herrero,Nima Mesgarani,Ashesh D Mehta

doi:10.1038/s41467-019-10611-4

Bahar Khalighinejad, Jose L Herrero + Show 2 more

Open Access

https://doi.org/10.1038/s41467-019-10611-4

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Abstract

Speech communication in real-world environments requires adaptation to changing acoustic conditions. How the human auditory cortex adapts as a new noise source appears in or disappears from the acoustic scene remain unclear. Here, we directly measured neural activity in the auditory cortex of six human subjects as they listened to speech with abruptly changing background noises. We report rapid and selective suppression of acoustic features of noise in the neural responses. This suppression results in enhanced representation and perception of speech acoustic features. The degree of adaptation to different background noises varies across neural sites and is predictable from the tuning properties and speech specificity of the sites. Moreover, adaptation to background noise is unaffected by the attentional focus of the listener. The convergence of these neural and perceptual effects reveals the intrinsic dynamic mechanisms that enable a listener to filter out irrelevant sound sources in a changing acoustic scene.

Highlights

IntroductionWe found variable numbers of electrodes with significant response changes during transitions to different background conditions (104 for jet, 120 for city, 122 for bar, and 78 for clean conditions, t-test, FDR corrected, p < 0.05; Supplementary Fig. 9)
Jet Clean City condition Bar Jet Speech3 s t-val High-gamma Z-score Intensity Waveform cNeural response dOriginal spectrogram eReconstructed spectrogram
We examined the dynamic reduction in background noise in the human auditory cortex using invasive electrophysiology combined with behavioral experiments

Summary

Introduction

We found variable numbers of electrodes with significant response changes during transitions to different background conditions (104 for jet, 120 for city, 122 for bar, and 78 for clean conditions, t-test, FDR corrected, p < 0.05; Supplementary Fig. 9). The secondary factor that further separates electrodes is their selective adaptation to different background noises The first three clusters all show minimal adaptation to the clean condition but have significant adaptation to jet, city, and bar noise, respectively. Clusters 4 and 5, on the other hand, Tier 1

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