Cochlea

The snail shaped organ of hearing in the inner ear

Overview

The cochlea is a fluid filled, spiral bony tube in the inner ear, coiled about two and a half turns and roughly the size of a pea. It contains three chambers, the scala vestibuli, scala media, and scala tympani, and the organ of Corti sits on the basilar membrane between them. Vibrations from the stapes create waves in the cochlear fluids that peak at different positions along the basilar membrane depending on frequency, high pitches near the base and low pitches near the apex. Hair cells convert this motion into electrical signals carried by the auditory nerve to the brain.