Audition Flashcards
amplitude corresponds to ____
frequency corresponds to ____
complexity corresponds to ____
amplitude»_space; loudness
freq»_space; pitch
complexity»_space; timbre
if a sound is 1000 times louder than reference, how many dB would it be?
60 dB (log10^1000 = 3 x 20)
adult humans detect frequencies between:
20hz to 20 Khz
what is the attenuation reflex?
Tightening of the stapedius and tensor tympani in response to loud noises to protect the ear. loss results in hyperacusis
tensor tympani is innervated by ____; stapedius by ___
tt»_space; trigeminal
stap»_space; facial
in the organ of Corti, stereo cilia deflected away from the kinocilia cause ____ while deflection toward results in ____
away» hyper polarization from K+ channel closing
toward»_space; depolarization from K+ channel opening
describe the compartments of the cochlea:
scala media (cochlear duct) separates the scala tympani and scala vestibuli. media contains endolymph; other two compartments contain perilymph. 80 mv difference across them. V & T connected by helicotrema
describe the basilar membrane of the cochlea and the where frequencies are localized:
wider and more flexible at apex, stiffer and narrower at base = high frequencies vibrate at base, low frequencies at apex.
afferent fibers innervate ____ hair cells, while efferent fibers from the ___ ____ innervate the ___ hair cells. Efferent response is activated in order to:
afferent»_space; inner
efferent from the superior olive»_space; outer
efferent»_space; dampen loud sounds
what changes in length do outer hair cells undergo in response to hyper/de polarization?
hyperpolarization»_space; lengthen
depolarization»_space; shortening
what is the contractile mechanism of the hair cells on the basilar membrane?
Prestin – motor protein on membrane
what is the cochlear amplifier? what are the advantages of this mechanism?
refers to the ability of the basilar membrane to change level of movement in response to levels of sound
advantages: dampen loud sound, drown out background noise and selectivity increase sensitivity to certain pitches
dorsal cochlear nuclei are important for detecting ___ while ventral is more for ___
dorsal»_space; frequency
ventral sends signals to superior olive for sound localization
describe how sound localization occurs:
below 3 Hz: time delay
above 3 Hz: intensity differences from each ear
where are time delays in sound detected?
the medial superior olive: coincidence detectors.
where is sound intensity for sound localization detected?
lateral superior olive: neurons stimulated ipsilaterally but inhibited from contralateral ear by inhibitory neurons in the medial trapezoid body.
integration of auditory information occurs in the:
inferior colliculus
from the inferior colliculus, signals travel to the:
medial geniculate nucleus of the thalamus
describe the specalizations of the primary and secondary auditory cortex:
primary: all cells columnar, receive tonotopic (best frequency) info
secondary: combinations of sounds used in vocalizations
what is Wernicke’s area?
posterior to primary auditory cortex. important for understanding speech. lesions»_space; jumbling of words and inability to comprehend speech
describe the ventral stream
primary auditory cortex and inferior frontal gyrus. specialized for pitch
describe the dorsal stream
superior frontal gyrus and superior parietal cortex. specializied for localization of sound
What is Broca’s area?
region in frontal cortex critical for producing speech
the supra marginal gyrus is important for:
distinguishing meaningful phonemes
