What part of the ear is primarily responsible for hearing?

The cochlea is indeed the part of the ear that is primarily responsible for hearing. It is a spiral-shaped, fluid-filled structure located in the inner ear. When sound waves enter the ear, they cause the eardrum (tympanic membrane) to vibrate. These vibrations then travel through the ossicles, a chain of small bones in the middle ear that amplify the sound. However, it is the cochlea that converts these mechanical vibrations into neural signals.

Inside the cochlea, there are hair cells lining the basilar membrane that detect the fluid's movement. When the sound waves cause the fluid to move, the hair cells bend, creating electrical signals that are sent to the brain via the auditory nerve. This process is crucial for perception of sound, making the cochlea the main organ for auditory processing.

The vestibule is involved in balance rather than hearing, and the eardrum and ossicles play supportive roles in the hearing process but do not directly convert sound waves into neural signals. Therefore, the cochlea is essential for the auditory experience.