In all Vertebrata the auditory vesicle undergoes further changes of a complicated kind.
The auditory vesicle in Mammalia is at first nearly spherical, and is imbedded in the mesoblast at the side of the hind-brain.
auditory vesicle n.
Either of the paired sacs of invaginated ectoderm in the embryo that develop into the membranous labyrinth of the internal ear. Also called otic vesicle.