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How does the medial geniculate nucleus relay auditory information?

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Diagram of a human brain showing a median sagittal section, highlighting the fourth ventricle and cerebellum in the hindbrain, with labeled anatomical structures including the pons, medulla oblongata, and central canal of the spinal cord. — thalamus Sagittal section of the human brain, showing structures of the cerebellum, brainstem, and cerebral ventricles.

The medial geniculate nucleus (MGN) serves as a critical relay station for auditory information within the thalamus. It receives input from the inferior colliculus as well as from the auditory cortex.1

The MGN is organized into three distinct regions, each responsible for processing different aspects of sound:

Ventral region: Relays information regarding frequency, intensity, and laterality.1
Dorsal region: Relays information concerning complex sounds.1
Medial region: Encodes relative sound properties.1

The MGN maintains a tonotopic organization—meaning it is arranged according to sound frequency—and maintains reciprocal output connections with the auditory cortex. From the MGN, there is an orderly projection of fibers to the primary acoustic area located in the temporal lobe of the cerebral cortex.12