auditory cortex
the sensory area for hearing, located on the upper side of the temporal lobe of the cerebral cortex. It receives and processes sound input from the medial geniculate nucleus in the thalamus, a major structure along the auditory pathway. Its main subdivision is the primary auditory cortex (A1), the first cortical region to receive this input. Equivalent to Brodmann’s area 41 and encompassing Heschl’s gyrus, A1 displays both frequency selectivity and tonotopic organization and is critical to the discrimination and localization of sounds. Neurons in A1 predominantly project to Wernicke’s area. Surrounding A1 is the secondary auditory cortex (A2, the “belt” or peripheral area), whose input from the medial geniculate nucleus is more diffuse, and its tonotopic organization less precise, than that of A1. It provides additional auditory
regulation to enhance A1 cortical processing. Also called auditory projection area.