How does the auditory nerve carry musical information to the brain?

The auditory nerve, specifically the cochlear nerve, serves as the vital conduit for transmitting musical information from the inner ear to the brainstem.12

The process begins when sound vibrations enter the inner ear, causing fluid in the cochlea to move and bend tiny hair cells within the organ of Corti. This mechanical movement triggers the release of neurotransmitters, which stimulate the nerve endings at the base of these hair cells to generate electrical signals.32

These signals travel along the primary auditory fibres—which originate in the spiral ganglion—and are bundled together to form the cochlear nerve trunk. The nerve then carries this encoded information into the medulla oblongata of the brainstem.134

Crucially, the spatial properties of the sound waves are preserved during this transmission through a phenomenon known as tonotopy, where different frequencies travel along distinct neural paths. Once in the brainstem, the information is relayed to the medial geniculate body and eventually to the auditory cortex for higher-order cognitive processing, transforming raw frequencies into the multidimensional experience of music.24