Adaptation of the human auditory cortex to changing background noise

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.

Signal processing in auditory cortex underlies degraded speech sound discrimination in noise

“…Our findings are consistent with recordings in human auditory cortex (Khalighinejad, Herrero et al 2019) where ongoing exposure to noise leads to suppression of cortical activity and enhanced neural and perceptual representation of speech sounds. However, our cortical inactivation results suggest that adaptation observed within cortex may not be cortical in origin, but rather may arise earlier in the ascending pathway.…”

Estimating and interpreting nonlinear receptive field of sensory neural responses with deep neural network models

“…This assumed model architecture thus limits the range of the nonlinear transformations that they can account for. This lack of a comprehensive yet interpretable computational framework has hindered our ability to understand the nonlinear signal transformations that are found ubiquitously in the sensory processing pathways ( Hong et al, 2008 ; Abbott, 1997 ; Khalighinejad et al, 2019 ).…”

Editorial. Probing the tract organization of language: Heschl’s gyrus fiber intersection area

“…7 This gyrus, known today as Heschl's gyrus, is understood to contain the primary auditory cortex, as it reliably exhibits tonotopic maps 3 (i.e., how sound frequencies map to different locations) presumably originating from the tonotopic maps encoded by the cochleae. Myriad investigations of Heschl's gyrus have been carried out related to many aspects of auditory processing, including developmental maturation, 15 normal auditory processing, 10 disorders of auditory processing such as autism, 18 pitch processing in musicians, 20 and auditory hallucinations in schizophrenia, 2 among many others. A number of techniques have been used to examine the auditory cortex, including transcranial direct current stimulation, 11 PET, 13 magnetoencephalography, 9 and functional MRI (fMRI).…”