Auditory Sensation & Perception (3.5)

hearing (audition)

- audition is the hearing that results from the transduction of vibrations in the air by the ears

- sound waves have frequency (pitch), and amplitude (volume)

parts of the ear

- the outer ear (pinna) collects sound waves and channels them through the ear canal until they reach the eardrum

- the middle ear channels the eardrum vibrations to the ossicles; hammer (malleus), anvil (incus), stirrup (staples); the ossicle vibrations are transmitted to the oval window

- the inner ear: vibration of the oval window is transmitted to the cochlea, which causes its fluid to move

pitch theories

- place theory: theory that links the pitch we hear to the place where the cochlea's membrane is stimulated

- frequency theory: theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to hear its pitch

       ~we sense pitch because the hair cells fire at different rates in the cochlea

deafness

- conduction deafness and sensorineural (nerve) deafness have different physiological bases

- what causes conduction deafness?... conventional hearing aids may restore hearing by amplifying the vibrations conducted by other facial bones to the cochlea

- what can cause sensorineural hearing loss?... cochlear implants can translate sounds into electrical signals, which are wired into the cochlea's nerves, conveying some information to the brain about incoming sounds

- sound localization: the process by which you determine the location of a sound; relies on stereophonic hearing