A distributed network of noise-resistant neuronsin the central auditory system

Abstract

Background noise strongly penalizes auditory perception of speech in humans or vocalizations in animals. Despite this, auditory neurons successfully detect and discriminate behaviorally salient sounds even when the signal-to-noise ratio is quite poor. Here, we collected neuronal recordings in cochlear nucleus, inferior colliculus, auditory thalamus, primary and secondary auditory cortex in response to vocalizations presented either against a stationary or a chorus noise. Using a clustering approach, we provide evidence that five behaviors exist at each level of the auditory system from neurons with high fidelity representations of the target, named target-specific neurons, mostly found in inferior colliculus and thalamus, to neurons with high fidelity representations of the noise, named masker-specific neurons mostly found in cochlear nucleus in stationary noise but in similar proportions in each structure in chorus noise. This indicates that the neural bases of auditory perception in noise rely on a distributed network along the auditory system.