Kathy, a neuroscience graduate student, is running the final experiments for her thesis, The Effects of Loud Noise on Auditory Perception. Kathy stimulates the auditory nerve of rodents exposed to loud noise and records the activity of neurons in the primary and secondary cortices. Through which brain pathway is sound input processed prior to arriving at the primary and secondary cortices?

Medulla - midbrain - thalamus.

Explanation:

Ear is one of the most important sense organs of our body that enable the organism to hear different sounds. Ear also maintain the equilibrium of the body.

The auditory nerve of the rodents passes through the brain and affect the primary and secondary cortices. The loud noise disturbs the auditory perception. The sound input through sensory nerves moves to the medulla of the brain. From the medulla, sound passes to the midbrain and finally into the thalamus prior reaching at the primary and secondary cortices of the brain.

Thus, the answer is Medulla - midbrain - thalamus.