PSYCH 3A03 Lecture Notes - Eustachian Tube, Impedance Matching, Cochlea

• School: McMaster University
• Department: Psychology
• Course: PSYCH 3A03
• Professor: Paul Faure

Document Summary

We have seen how airborne vibrations are generated, propagated, and dissipated by the environment. Next we will see how these mechanical vibrations are converted into hydrodynamic (fluid) vibrations before encoded as electrochemical (neural) impulses. Acoustic energy is collected (funnelled) by the outer ear and then impinges on the eardrum (tympanic membrane) This mechanical energy is transmitted to the middle ear via a chain of small bones, the middle ear ossicles. The middle ear converts mechanical vibrations into fluid pressure changes inside the inner ear (cochlea) Lateral portion is considered to be the external ear. Eustachian tube (cavity that connects to the nasal pharynx) Pressure changes in cochlear fluids are used to generate neural impulses (action potentials) for analysis by cns. Vestibular neurons on the cochlea and vestibule forming the auditory nerve. Outer and middle ears allow for very efficient transfer of the acoustic stimulus (sound energy into neural energy)