Auditory cortex achieves noise-and-reverberation-invariance that brainstem processing lacks.

Evidence

The differential effects of noise and reverberation on speech representations in the early stages of brain-stem neural processing are in clear contrast to noiseand reverberation-invariant representations of speech in auditory cortex (Mesgarani et al. 2014 ). Perhaps one clue to the neural underpinnings of robust speech understanding in challenging acoustic environments is compensation for the effects of reverberation on coding of temporal-envelope modulation in the inferior colliculus, based on sensitivity to inter-aural correlation (Slama and Delgutte 2015 ). What is clear from our data is that neurophysiological effects of room reverberation cannot simply be assimilated to those of broadband noise for signal detection and discrimination. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5070

Categorization

• QUESTION: The inferior colliculus inter-aural correlation compensation hypothesis is flagged as tentative (“perhaps one clue”) — worth chasing how that mechanism works.