Final answer:
A tonotopic region is a region in the ear or the brain containing cilia or neurons that respond to specific frequencies. The hair cells in the tonotopic region of the cochlea are responsible for processing sound by responding to different frequencies.
Step-by-step explanation:
A tonotopic region is one of the regions in the ear or the brain that contains cilia or neurons that respond to specific frequencies. Specifically, the hair cells in the tonotopic region of the cochlea are responsible for processing sound by responding to different frequencies. Each hair cell is sensitive to a particular frequency and allows the cochlea to separate auditory stimuli by frequency.