Which part of the ear is responsible for frequency separation during hearing?

The cochlea is the part of the ear responsible for frequency separation during hearing. It is a spiral-shaped structure filled with fluid and is integral to the auditory system. Within the cochlea, there are specialized cells known as hair cells that respond to different sound frequencies. This separation occurs along the basilar membrane, where different areas vibrate in response to specific frequencies of sound. Higher frequencies activate hair cells located at the base of the cochlea, while lower frequencies stimulate those towards the apex. This tonotopic organization allows the brain to perceive a wide range of sounds effectively.

The other options listed pertain to different components of the ear. The malleus, incus, and stapes are all ossicles located in the middle ear, responsible for transmitting sound vibrations from the eardrum to the cochlea, but they do not separate frequencies. Their primary function is to amplify sound rather than process different frequency ranges.