Which structure in the ear is responsible for converting sound vibrations into neural signals?

The cochlea is the structure in the ear responsible for converting sound vibrations into neural signals. It is a spiral-shaped, fluid-filled organ located in the inner ear. When sound waves enter the ear, they first vibrate the eardrum, which then transmits these vibrations to the bones of the middle ear, known as the ossicles. The ossicles amplify the sound and send it to the cochlea.

Inside the cochlea, there are specialized hair cells that respond to the fluid movements caused by the sound vibrations. When these hair cells move, they convert the mechanical energy of the vibrations into electrical signals—a process known as transduction. These electrical signals are then sent to the brain via the auditory nerve, where they are interpreted as sound.

The outer ear, ear canal, and eardrum play supportive roles in the hearing process but do not themselves convert vibrations into electrical signals. The outer ear helps to capture sound waves, the ear canal directs these sound waves towards the eardrum, and the eardrum vibrates in response to the sound waves. However, it is specifically the cochlea that performs the vital function of translating those vibrations into a form that the nervous system can understand.