where does transduction take place in the ear
Transduction (physiology) In the auditory system, sound vibrations (mechanical energy) are transduced into electrical energy by hair cells in the inner ear. Sound vibrations from an object cause vibrations in air molecules, which in turn, vibrate the ear drum. The movement of the eardrum causes the bones of the middle ear (the ossicles) to vibrate.[5][6] These vibrations then pass into the cochlea, the organ of hearing. Within the cochlea, the hair cells on the sensory epithelium of the organ of Corti bend and cause movement of the basilar membrane. The membrane undulates in different sized waves according to the frequency of the sound. Hair cells are then able to convert this movement (mechanical energy) into electrical signals (graded receptor potentials) which travel along auditory nerves to hearing centres in the brain.[7]
Inner ear In the middle ear, the energy of pressure waves is translated into mechanical vibrations by the three auditory ossicles. Pressure waves move the tympanic membrane which in turns moves the malleus, the first bone of the middle ear. The malleus articulates to incus which connects to the stapes. The footplate of the stapes connects to the oval window, the beginning of the inner ear. When the stapes presses on the oval window, it causes the perilymph, the liquid of the inner ear to move. The middle ear thus serves to convert the energy from sound pressure waves to a force upon the perilymph of the inner ear. The oval window has only approximately 1/18 the area of the tympanic membrane and thus produces a higher pressure. The cochlea propagates these mechanical signals as waves in the fluid and membranes, and then converts them to nerve impulses which are transmitted to the brain.[3]