Auditory Pathway

From ear to cortex, the brain hearing highway

Overview

Auditory nerve fibers synapse in cochlear nuclei, cross to superior olive, first binaural comparison station, ascend lateral lemniscus to inferior colliculus, medial geniculate, then auditory cortex. Unlike vision, information crosses and recrosses, each ear feeds both hemispheres, so single sided brain lesions rarely deafen an ear. The pathway is tonotopic throughout and heavily descending, cortex to cochlea, efferent control, the brain modulates its own input. Processing is fast, 10 ms to brainstem, enabling millisecond localization judgments.