Which part of the ear vibrates in response to sound waves and sends these vibrations to the ossicles?

The eardrum, also known as the tympanic membrane, plays a crucial role in the process of hearing. When sound waves enter the ear, they travel through the auditory canal and reach the eardrum. The eardrum vibrates in response to these sound waves, and these vibrations are then transmitted to the ossicles, which are a series of small bones in the middle ear. This is a key step in the process of converting sound waves into signals the brain can interpret. The vibrations of the eardrum are essential for amplifying the sound before it reaches the inner ear.

In contrast, the pinna is the visible part of the ear that captures sound waves but does not vibrate in response to them. The auditory canal simply serves as a passageway for sound to travel to the eardrum. Finally, the cochlea is involved in the processing of sound signals after they have been transmitted by the ossicles, but it does not directly respond to sound waves. Understanding the function of the eardrum highlights its importance in the auditory system and how it initiates the hearing process.