THE EAR
There is no auricle; the external ear consists only of the external acoustic meatus, which opens on the side of the head under cover of a patch of small feathers. The meatus is short and straight, so the relatively large tympanic membrane can easily be examined (and as easily injured).
A lobe, similar in structure to comb and wattle, is present ventral to the opening (Figure 37-1Z4). Among domestic chickens, the color of the ear lobe matches the color of the shell of the eggs the hen lays.The middle ear resembles that of mammals, except for the modification of the ossicles. The tympanic membrane is connected to the vestibule window by the columella and the homologue of the mammalian stapes, a tiny osseous rod expanded at each end.
The structure and subdivision of the inner ear follow the mammalian pattern. The cochlea does not form a spiral and is only slightly curved, although it is significantly shorter than its mammalian counterpart; a relatively thick layer of sensory cells seems to compensate for brevity.