cochlea

from WordNet (r) 3.0 (2006)

cochlea
    n 1: the snail-shaped tube (in the inner ear coiled around the
         modiolus) where sound vibrations are converted into nerve
         impulses by the organ of Corti

from The Collaborative International Dictionary of English v.0.48

Cochlea \Coch"le*a\ (k[o^]k"l[-e]*[.a]), n. [L., a snail, or
   snail shell, Gr. kochli`as a snail, fr. ko`chlos a shellfish
   with a spiral shell.] (Anat.)
   An appendage of the labyrinth of the internal ear, which is
   elongated and coiled into a spiral in mammals. See {Ear}.
   [1913 Webster]