What happens to the eardrum in response to sound?

The eardrum, also known as the tympanic membrane, plays a crucial role in the process of hearing. When sound waves enter the ear, they create changes in air pressure that hit the eardrum. This pressure causes the eardrum to vibrate. These vibrations are then transmitted through the ossicles, small bones in the middle ear, to the inner ear, where they are converted into nerve impulses that the brain interprets as sound.

The vibration of the eardrum is essential for amplifying the sound signals and is the first step in the auditory process. Without these vibrations, sound would not be effectively transmitted from the outer ear to the inner ear structures. This highlights why the option stating that the eardrum vibrates in response to sound is the accurate choice in describing the response of the eardrum to auditory stimuli.