glossary

ear

Definition ear

earhol

ear n. the sence orgon concerned with hearing and balance (see illustrstion). Sound waves, transmitted from the outside into the external auditory meatus, cause the eardrum (tympanic membrane) to vibrate. The small bones (ossicles) of the middle ear - the malleus, incus, and stapes - trasmit the sound vibrations to the fenestra ovalis, which leads to the inner ear (see labyrinth). Inside the *cochlea the sound vibrations are converted into nerve impulses. Vibrations emerging from the cochlea. could cause pressure to build up inside the ear, but this is released through the *Eustachian tube. The *semicircular canal, *saccule, and *utricle - also in the inner ear - are all concerned with balance.