Development of the neural signatures of stream segregation from childhood to adulthood

When faced with noisy environments, listeners perform auditory scene analysis, which allows them to selectively focus on the relevant auditory target while ignoring interferences. Stream segregation involves organizing similar sound waves into a coherent stream, while distinguishing dissimilar acoustic components and attributing them to distinct sources. Two event-related potential components have been identified as “neural signatures” of stream segregation: the Object-Related Negativity (ORN) and the P400. Our study aims to examine (i) the maturation of neural correlates of stream segregation and (ii) the development of the relationship between these neural correlates and speech perception in noise. ORN/P400 were recorded while 8–23 year-olds (n = 75) performed an active stream segregation task based on temporal coherence. Participants also performed speech identification in noise tasks (behaviorally). Behavioral results indicate an improvement in both stream segregation and speech perception in noise from childhood to adulthood. The amplitude of the ORN (but not P400) decreases, and the latency of both ORN and P400 decreases throughout development. Critically, P400 amplitude significantly predicts stream segregation performance. Overall, our results suggest that the neural mechanisms underlying stream segregation follow a prolonged maturation trajectory, and support the progressive maturation of auditory scene analysis and speech perception in noise.