ABSTRACT
The outer and middle ear of all vertebrates serve as a “sensory accessory structure” designed to focus and funnel vibratory energy from the external environment to the fluid-filled chambers of the inner ear. In the process, the efficiency of sound energy transfer from air (in the case of terrestrial animals) to the inner ear is improved. This improvement occurs through interactions between the sound field and the head, body, pinna, and ear canal (external meatus) of the outer ear, and the conducting aparatus of the middle ear (McDonogh, 1986; Chen et al., 1995).
