SLHS 340 - Exam 1 Questions and Answers Fully Solved
outer ear - Answers - auricle
- ear canal
middle ear - Answers - tympanic membrane
- ossicles
inner ear - Answers - cochlea
- auditory nerve
cochlea - Answers - organ of corti --> stereocilia touches the tectorial membrane, allows the basilar
membrane to move in resonance in order to amplify displacement (like pumping your legs on a swing) of
tectorial and basilar membrane in order to move the inner hair cells in order to detect sound
(inner hair cells are not initially in contact with the tectorial membrane)
- scala vestibuli, scala media, scala tympani
cochlear mechanics - Answers zooming in on inner hair cell
1) basilar membrane is displaced up, bending the stereocilia towards the tallest one
2) ion channels open
3) K+ & Ca2+ ions enter the hair cell, depolarizing the cell (bringing back to resting) --> -20 to -40-45
how is the cochlea organized? - Answers tonotopically
which hair cells are vibrating gives the brain an indication of the pitch of the sound
low frequencies (cochlear mechanics) - Answers - maximum displacement of the basilar membrane is
the APICAL end (top/peak) --> resonance frequencies
high frequencies (cochlear mechanics) - Answers - maximum displacement of the basilar membrane is
the BASAL end (the beginning/bottom)
- where the stapes footplate is pushing on the oval window
air conduction (AC) - Answers - collect sound vibrations with the ear canal/auricle --> middle ear -->
inner ear --> up to brain
- the process by which sound waves enter the ear through the pinna
,- when normal, there should be
- sound is being conducted through the air
- when testing, using diff transducers: headphones, super-aural headphones or inserts. aka anything we
can apply to the auricles to send sound through the FULL hearing pathway. not bypassing by sending
something via bone conduction
bone conduction (BC) - Answers - occurs as the eardrum vibrates and moves the auditory ossicles
- when there's a stimulus or transducer that applies vibration directly to the bone, it vibrates the bone as
well as the fluid within the cochlea
- when testing, uses an oscillator that is placed on top of the mastoid bone in order to send vibrations to
the tympanic membrane in order to mimic the function of the middle ear, sending the sound straight to
the inner ear
conductive mechanism - Answers - outer to middle ear
- normal AC (outer ear)
sensorineural mechanism - Answers - inner ear to auditory nerve to brain
- normal BC (inner ear)
audiogram - Answers - graphic record of hearing
- high x-axis: high frequency
- high y-axis: hearing level is loud
- most of the freq. of speech are at the top of the graph
- better hearing = top of graph
left ear (audiogram symbols) - Answers - X (AC - unmasked; presenting sound)
- square (AC - masked; actively distracting non-test ear)
- > (BC - unmasked)
- ] (BC - masked)
right ear (audiogram symbols) - Answers - circle (AC - unmasked)
- triangle (AC - masked)
- < (BC - unmasked)
, - [ (BC - masked)
left ear - NO response (audiogram symbols) - Answers - X arrow down right (AC - unmasked)
- square arrow down right (AC - masked)
- > arrow down right (BC - unmasked)
- ] arrow down right (BC - masked)
- arrow: pointing in diff directions because on the graph (and where we place things) it will allow us to
designate where is the patient's left and right (ex: left arrow on right ear bc that's what it looks like to
you)
right ear - NO response (audiogram symbols) - Answers - circle arrow down left (AC - unmasked)
- triangle arrow down left (AC - masked)
- < arrow down left (BC - unmasked)
- [ arrow down left (BC - masked)
degrees of hearing loss - Answers normal (-10 to 25 dB HL)
mild (26 to 40 dB HL)
moderate (41 to 55 dB HL)
moderately severe (56 to 70 dB HL)
severe (71 to 90 dB HL)
profound (> 90 dB HL)
degrees of hearing loss - children - Answers normal (-10 to 15 dB HL)
slight (16 to 25 dB HL)
normal is divided into two categories because slight hearing loss can produce educationally significant
effects
normal hearing - Answers - (-)10 to 25 dB HL
- normal AC
- normal BC
outer ear - Answers - auricle
- ear canal
middle ear - Answers - tympanic membrane
- ossicles
inner ear - Answers - cochlea
- auditory nerve
cochlea - Answers - organ of corti --> stereocilia touches the tectorial membrane, allows the basilar
membrane to move in resonance in order to amplify displacement (like pumping your legs on a swing) of
tectorial and basilar membrane in order to move the inner hair cells in order to detect sound
(inner hair cells are not initially in contact with the tectorial membrane)
- scala vestibuli, scala media, scala tympani
cochlear mechanics - Answers zooming in on inner hair cell
1) basilar membrane is displaced up, bending the stereocilia towards the tallest one
2) ion channels open
3) K+ & Ca2+ ions enter the hair cell, depolarizing the cell (bringing back to resting) --> -20 to -40-45
how is the cochlea organized? - Answers tonotopically
which hair cells are vibrating gives the brain an indication of the pitch of the sound
low frequencies (cochlear mechanics) - Answers - maximum displacement of the basilar membrane is
the APICAL end (top/peak) --> resonance frequencies
high frequencies (cochlear mechanics) - Answers - maximum displacement of the basilar membrane is
the BASAL end (the beginning/bottom)
- where the stapes footplate is pushing on the oval window
air conduction (AC) - Answers - collect sound vibrations with the ear canal/auricle --> middle ear -->
inner ear --> up to brain
- the process by which sound waves enter the ear through the pinna
,- when normal, there should be
- sound is being conducted through the air
- when testing, using diff transducers: headphones, super-aural headphones or inserts. aka anything we
can apply to the auricles to send sound through the FULL hearing pathway. not bypassing by sending
something via bone conduction
bone conduction (BC) - Answers - occurs as the eardrum vibrates and moves the auditory ossicles
- when there's a stimulus or transducer that applies vibration directly to the bone, it vibrates the bone as
well as the fluid within the cochlea
- when testing, uses an oscillator that is placed on top of the mastoid bone in order to send vibrations to
the tympanic membrane in order to mimic the function of the middle ear, sending the sound straight to
the inner ear
conductive mechanism - Answers - outer to middle ear
- normal AC (outer ear)
sensorineural mechanism - Answers - inner ear to auditory nerve to brain
- normal BC (inner ear)
audiogram - Answers - graphic record of hearing
- high x-axis: high frequency
- high y-axis: hearing level is loud
- most of the freq. of speech are at the top of the graph
- better hearing = top of graph
left ear (audiogram symbols) - Answers - X (AC - unmasked; presenting sound)
- square (AC - masked; actively distracting non-test ear)
- > (BC - unmasked)
- ] (BC - masked)
right ear (audiogram symbols) - Answers - circle (AC - unmasked)
- triangle (AC - masked)
- < (BC - unmasked)
, - [ (BC - masked)
left ear - NO response (audiogram symbols) - Answers - X arrow down right (AC - unmasked)
- square arrow down right (AC - masked)
- > arrow down right (BC - unmasked)
- ] arrow down right (BC - masked)
- arrow: pointing in diff directions because on the graph (and where we place things) it will allow us to
designate where is the patient's left and right (ex: left arrow on right ear bc that's what it looks like to
you)
right ear - NO response (audiogram symbols) - Answers - circle arrow down left (AC - unmasked)
- triangle arrow down left (AC - masked)
- < arrow down left (BC - unmasked)
- [ arrow down left (BC - masked)
degrees of hearing loss - Answers normal (-10 to 25 dB HL)
mild (26 to 40 dB HL)
moderate (41 to 55 dB HL)
moderately severe (56 to 70 dB HL)
severe (71 to 90 dB HL)
profound (> 90 dB HL)
degrees of hearing loss - children - Answers normal (-10 to 15 dB HL)
slight (16 to 25 dB HL)
normal is divided into two categories because slight hearing loss can produce educationally significant
effects
normal hearing - Answers - (-)10 to 25 dB HL
- normal AC
- normal BC
