<Tr> <Td> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The cochlea / ˈkɒk. liə / (Ancient Greek: κοχλίας, kōhlias, meaning spiral or snail shell) is the auditory portion of the inner ear . It is a spiral - shaped cavity in the bony labyrinth, in humans making 2.5 turns around its axis, the modiolus . A core component of the cochlea is the Organ of Corti, the sensory organ of hearing, which is distributed along the partition separating fluid chambers in the coiled tapered tube of the cochlea . The name is derived from the Latin word for snail shell, which in turn is from the Greek κοχλίας kokhlias ("snail, screw"), from κόχλος kokhlos ("spiral shell") in reference to its coiled shape; the cochlea is coiled in mammals with the exception of monotremes . </P> <P> The cochlea (plural is cochleae) is a spiralled, hollow, conical chamber of bone, in which waves propagate from the base (near the middle ear and the oval window) to the apex (the top or center of the spiral). Rosenthal's canal or the spiral canal of the cochlea is a section of the bony labyrinth of the inner ear that is approximately 30 mm long and makes 23⁄4 turns about the modiolus . The cochlear structures include: </P>

The coiled bony fluid-filled tube in the inner ear that houses the sensory receptors is called the