Hearing and Perception Flashcards
what is the law of specific nerve endings
cortical neurons communicate by spikes
the neural pathway carrying the signal determines sensation
what are the two theories of pitch perception
place code
temporal code
provide a review of peropheral auditory organisation
ear canal
ear drum= vibration= mechanical bone changes
cochlea- fluid and frequencies seperated
hgih at base low at end
describe the movement in the basiliar membrane for pure tones
each point on membrane oscillates up and down at same frequency as tone
what differs is size of oscillation
what is the cochlear membrane
microphonic small electrical signal that can be measured near hair cells
describe cochlear membrane and low and high frequencies
low= slow firing rates high= high firing
what is temporal code theory
pitch is coded by firing rates of cells in 8th auditory nerve
what are two problems with temporal code theory
single cells firing rate is limited
hearing range is limited
how does temporal code work
volley principle
what is volley principle
idea stating multiple neurons can provide a temporal code for frequency as each neuron fires at a distinct point in period of a sound wave but does not fire on every perios
how do microphone transmitters work
implanted electrodes into cochlea
muct stimulate cohclea
which of the coding theories is best
both play a role
temporal used for low frequencies
place useful for high frequencies
what is interaural time difference
difference in time between a sound arriving at one ear vs the other
when is ITD most usefil
for low frequencies
as we need to be able to link features
what is interaural level difference
difference in intensity between a sound arriving at one ear vs the other
when are sounds more intense
at ear closest to sound
what are ITD and ILD great for
determining azimuth
what is the cone of confusion
regions in space where all sounds produce the same time and level differences
what is the inverse square law
as distance from source icreases, intensity decreases faster such that decrease in intensty is distance squared
descirbe spectral compositions of sounds
higher frequencies decrease in energy more than lower frequencies as sound waves travel from source to one ear
what is source segregation or aufitory scene analysis
perceptual organisation of a complex accoustic signal into separate auditory events for which each stream is heard as a separate event
