All parts of the brain › Hearing

What part of the brain controls hearing?

Mainly the auditory cortex, on the upper surface of the superior temporal gyrus. Sound climbs to it through relays: the cochlear nuclei in the medulla, the superior olivary complex in the pons (where the two ears are compared), the inferior colliculus in the midbrain and the medial geniculate nucleus of the thalamus. These relays are small nuclei, not separate shapes on this model, so the whole medulla, pons, midbrain and thalamus light. [1][2][3][4][5][6]

The auditory cortex are regions on these gyri, not separate shapes. The 3D model draws only whole gyri, so the gyrus that holds each area is lit; the area’s exact border is not drawn.

The 3D brain needs JavaScript. The list of parts still says what each one does for hearing.

Slice

All 6 parts are lit together. Drag to turn, pinch or scroll to zoom, tap a part on the brain or a name in the list to focus it; .

Hearing: 6 parts lit

Superior temporal gyrus, thalamus, midbrain, pons, medulla oblongata and temporal lobe. Tap one to see where it is and what it does.

The parts and their roles

Holds the auditory cortex: the primary auditory cortex on Heschl’s gyrus, the first cortex to receive sound, and the belt and parabelt areas around it that work on more complex sounds. [2][7] Where is the superior temporal gyrus?
Its medial geniculate nucleus (not a separate shape on this model yet) is the thalamic relay between the inferior colliculus and the auditory cortex. [5] Where is the thalamus?
Its inferior colliculus (not a separate shape on this model yet), on the lower roof of the midbrain, is the main auditory nucleus of the midbrain, where nearly all ascending hearing paths converge before the thalamus. [4] Where is the midbrain?
Its superior olivary complex is the first place where the signals from the two ears meet: it compares when and how loud a sound arrives at each ear to tell where the sound comes from. [8] Where is the pons?
The auditory nerve enters the brainstem at the pontomedullary junction and ends in the cochlear nuclei on its side, the first stop in the brain for every signal from the cochlea. [3][6] Where is the medulla oblongata?
The lobe that holds the auditory cortex; it processes sound and, in the areas around the auditory cortex, links sounds to meaning, including spoken words. [9][2] Where is the temporal lobe?

Named areas on the lit gyri

Auditory cortex, on the : On the upper surface of the superior temporal gyrus, partly hidden in the lateral sulcus: the primary auditory cortex on Heschl’s gyrus (the transverse temporal gyri, roughly Brodmann area 41) with belt and parabelt areas around it (roughly area 42); it is laid out by pitch, from low to high. [2][10]

How they work together

The cochlea splits sound by pitch, high notes at its base and low notes at its tip, and that order (tonotopy) is kept at every relay up to the auditory cortex, which holds a map from low to high pitch. [1][11]
From the superior olivary complex upward each side of the brain gets input from both ears, so each auditory cortex hears both ears, with the opposite ear usually somewhat stronger. [1][8]
Where a sound comes from is worked out in the brainstem: the medial superior olive compares the tiny difference in arrival time at the two ears, and the lateral superior olive the difference in loudness. [8]
Honest limit: the cochlear nuclei, superior olivary complex, inferior colliculus and medial geniculate nucleus are small nuclei with no shape of their own on this model, so the whole medulla, pons, midbrain and thalamus light; the auditory cortex is a region on the superior temporal gyrus, so the whole gyrus lights; and the ear and auditory nerve themselves are outside the brain and not drawn. [1][2]

Sources

Facts describe anatomy and normal function only. A part lit here takes part in hearing; it does not do it alone, and it does other jobs too. The 3D model is the adult male BodyParts3D brain (credits and licence); on it the brainstem includes the midbrain, pons and medulla, so lighting the brainstem lights all three.