The auditory center, in the brain, shown above in red, is concerned with hearing. Although shown here on the outer surface of the brain, most of this area lies within the temporal lobes and is found within the surface of the cerebral cortex on both sides of the brain. The auditory pathways begin in the nerve fibers of the organ of Corti in the inner ear, where sound waves are converted to nerve impulses. These impulses travel in the auditory nerve to the auditory cortex of the brain. During their passage to the auditory center, some of the auditory nerve fibers cross in the brain stem. This results in the sound which enters one ear passing to both cortices. The impulses are relayed in the lateral lemnisci and from there, via the medial geniculate nuclei, to the auditory cortices in the temporal lobes of the brain, where sound is perceived.