Hearing and Brain

Tectorial membrane

moves back and forth from vibrations

Stereocilia

tips of hair cells

Outer hair cells

‘tuning’ mostly connection from the brain

Basilar membrane

base of hair cells

Auditory nerve

sends/receives signals to/from brain

Inner hair cells

transduce mechanical to electrical signal, send signal to brain

Organ of corti

hair cells and dendrites of auditory nerve fibers

role of outer hair cells

change their shape and rigidity to control the motion of the basilar membrane, amplifying weak sounds and attenuating loud sounds (‘tuning’)

Electromotility

ability to lengthen and contract in response to changes in electric potential

Cochlear nucleus

first brain stem nucleus where afferent auditory nerve fibers synapse

Superior olive

early brain stem region in auditory pathway where inputs from both ears converge

Inferior colliculus

midbrain nucleus

Medial geniculate nucleus

part of the thalamus, relays auditory signal to/from auditory cortex

A1/Auditory cortex

first area in the temporal lobes responsible for processing acoustic signals

Bilateral damage

cortical deafness

causes of hearing loss

obstruction to ear canal, sensorineural hearing loss, conducting hearing loss

Sensorineural hearing loss

damage to parts of cochlea or auditory nerve

Conductive hearing loss

reduced ability of middle ear bones to conduct vibrations from tympanic membrane to oval window

prevent hearings loss

lower volume on devices, wear earplugs, avoiding turning up volume to compensate for loud environments

noise cancelling devices

Capture background noise accurately enough in real time so the device can cancel it out, before it is processed by your ear