Hearing Flashcards
What is sound
longitudinal waves - rapid variation of air pressure
What is wavelength and frequence
WL - distance between two peaks
FR - rate the pressure cycles compression > refraction
normal air pressure?
100kpa
what is a decibel?
100kpa =
log
2 mil decibels
role of the pinna
gathers air from around and funnels into eardrum
what is the cochlea
fluid filled spiral canal separated by a flexible membrane
differences between two sides of the cochlea
start narrow and stiff end wide and compliant
what does the wave in the cochlea determine
frequency
where is the organ of corti
within the scalia media
shapes of inner hair cells and outer hair cells
inner - fat
outer - thin
what to the stereocilla look like of inner and outer hair cells
inner hair cells - in a line
outer - rows of 3 in dome shames
how do the hair cells work
the hair cells bend one way causing depolarisation and bend another way causing repolarisation. the hair cells are attached to afferent neurones so APs are generated during depolarisation (right excitation left inhibition)
what are transduction links
in hair cells join the cillia together causing increased ion entry making the depol / hyperpol bigger
tuning fork?
high kh lower decibels and at a higher decibels at a lower hhz
What is the cochlear amplifier
theyre motile therefor increased vibrations in the basilar membrane - amplifies quiet sound not loud
