Auditory system (Sensation vs perception )

pinna

the visible outer ear

auditory canal directs

sound waves toward eardrum

tympanic membrane (eardrum)

vibrates when sound waves hit it

Ossicles-middle ear

3 tiny bones transmit the vibrations

malleus

hammer

incus

anvil

stapes

stirrup

Oval window and cochlea

Stapes presses against oval window, making fluid inside cochlea move

Basilar membrane and hair cells

Fluid movement stimulates hair cells, which convert mechanical stimulation into neural impulses

Auditory nerve and brain

Info travels throu auditory nerve to inferior colliculus, medical geniculate nucleus of thalamus, finally auditory cortex in temporal lobe

pitch definition

how high or low a sound seems

low frequency =

low pitch

High frequency =

high pitch

Temporal theory

pitch is encoded by the firing rate of sensory neurons

rate of neural impulses corresponds to

sound’s frequency

temporal theory limitation

neurons cant fire fast enough to encode the entire human hearing range of 20-20000 Hz using firing rate alone

place theory

pitch is encoded by where the basilar membrane responds most strongly