ISCA Archive Interspeech 2024
ISCA Archive Interspeech 2024

From Sound to Meaning in the Auditory Cortex: A Neuronal Representation and Classification Analysis

Kumar Neelabh, Vishnu Sreekumar

The neural mechanisms underlying the comprehension of meaningful sounds are yet to be fully understood. While previous work has shown that the auditory cortex can classify auditory stimuli into distinct semantic categories, the specific functions of the primary (A1) and the secondary auditory cortex (A2) are not well understood. We analyzed the neural responses of songbirds as they listened to their entire vocal repertoire. We first show that the distances between semantic categories in acoustic and neural representations are correlated in both A1 and A2. We then show that while both A1 and A2 are equally informative of the acoustic category of the vocalizations, A2 is significantly more informative of their semantic category. Additionally, we show that the semantic categories are more separated in A2. These findings suggest that as the incoming signal moves downstream within the auditory cortex, its acoustic information is preserved, while its semantic information is enhanced.