Hearing Aid Dispenser Written Exam
UPDATED ACTUAL Questions and
CORRECT Answers
db loss of a perforation of TM - CORRECT ANSWER - 10-15db loss
procedure done to fix perforation - CORRECT ANSWER - tympanoplasty or
myringoplasty
monomeric spots - CORRECT ANSWER - looks like a hole in TM, but reflects light like a
mirror. holes that have healed. aka "mirror membranes"
average dimentions of an adult eardrum - CORRECT ANSWER - 2.3-2.9cm in length,
.7cm in diameters
pars tensa - CORRECT ANSWER - lower 4/5 of TM and tight
pars flaccida - CORRECT ANSWER - upper 1/5 of TM and flaccid
otis externa - CORRECT ANSWER - "swimmers ear" - inflammation of the walls of the
EAM. will not cause loss unless swelling blocks canal. treat: warm salt water, drying it, topical
antibiotics
polyps - CORRECT ANSWER - masses of tissue that grow outward from a surface
cholesteatoma - CORRECT ANSWER - non-cancerous tumor in the middle ear. oderous
discharge. sometimes perforates upper TM. invasions of skin into the middle ear - sac of
concentric rings of protein. causes conductive loss. most dangerous pathology.
,enlarged canal - CORRECT ANSWER - result of ear surgery. often have no ear drum or
ossicular chain. need approval of physician before fitting
tympanosclerosis - CORRECT ANSWER - white, chalky calcium deposits caused by
degeneration of tissue on eardrum, thicking and scarring from peforations and infections
epitympanic cavity - CORRECT ANSWER - attic of middle ear. allows air into mastoid
cells of temporal bone. branches several nerves
incudotapedial junction - CORRECT ANSWER - top of incus to head of stapes
annular ligament - CORRECT ANSWER - footplate of stapes that is held in the oval
window
speed of sound - CORRECT ANSWER - 700mph or 340 m/s (4x as fast through water,
14x as fast through steel)
reflection - CORRECT ANSWER - is an echo or a reverberation
reverberation - CORRECT ANSWER - often in a small room, 17m or less, reverbs can
mask high frequencies
echo - CORRECT ANSWER - heard and perceived later than original sound (more than
1/10s after)
absorption - CORRECT ANSWER - aborbs sound. can improve environments w/
reflection or reverb. better in warmth and moist
diffraction - CORRECT ANSWER - sharpness in the change in direction of sound,
bending. high diffraction=bigger wavelengths (low freq)
, refraction - CORRECT ANSWER - sound passes through one medium to another, change
in speed and wavelength
infrasound - CORRECT ANSWER - below audible range of 20 Hz
ultrasound - CORRECT ANSWER - above audible range of 20K Hz
octave - CORRECT ANSWER - anytime the frequency doubles. f(2) = on octave; f(3)=
two octaves
faintest sound a human can hear - CORRECT ANSWER - 10 ^ -16 watts/cm^2 and
pressure of .0002 dynes/cm^2
threshold of pain - CORRECT ANSWER - 1000 dynes/cm^2
when SPL levels double how many db levels increase? - CORRECT ANSWER - 6 db
db HL expresses: - CORRECT ANSWER - threshold levels
db SPL expresses: - CORRECT ANSWER - voices or environmental sounds
pinna function: - CORRECT ANSWER - gather sound, aid in localization, enahnce high
freq bw 2k-5k hz
aperture - CORRECT ANSWER - entrance to canal, first bend
isthmus - CORRECT ANSWER - narrowing of canal
UPDATED ACTUAL Questions and
CORRECT Answers
db loss of a perforation of TM - CORRECT ANSWER - 10-15db loss
procedure done to fix perforation - CORRECT ANSWER - tympanoplasty or
myringoplasty
monomeric spots - CORRECT ANSWER - looks like a hole in TM, but reflects light like a
mirror. holes that have healed. aka "mirror membranes"
average dimentions of an adult eardrum - CORRECT ANSWER - 2.3-2.9cm in length,
.7cm in diameters
pars tensa - CORRECT ANSWER - lower 4/5 of TM and tight
pars flaccida - CORRECT ANSWER - upper 1/5 of TM and flaccid
otis externa - CORRECT ANSWER - "swimmers ear" - inflammation of the walls of the
EAM. will not cause loss unless swelling blocks canal. treat: warm salt water, drying it, topical
antibiotics
polyps - CORRECT ANSWER - masses of tissue that grow outward from a surface
cholesteatoma - CORRECT ANSWER - non-cancerous tumor in the middle ear. oderous
discharge. sometimes perforates upper TM. invasions of skin into the middle ear - sac of
concentric rings of protein. causes conductive loss. most dangerous pathology.
,enlarged canal - CORRECT ANSWER - result of ear surgery. often have no ear drum or
ossicular chain. need approval of physician before fitting
tympanosclerosis - CORRECT ANSWER - white, chalky calcium deposits caused by
degeneration of tissue on eardrum, thicking and scarring from peforations and infections
epitympanic cavity - CORRECT ANSWER - attic of middle ear. allows air into mastoid
cells of temporal bone. branches several nerves
incudotapedial junction - CORRECT ANSWER - top of incus to head of stapes
annular ligament - CORRECT ANSWER - footplate of stapes that is held in the oval
window
speed of sound - CORRECT ANSWER - 700mph or 340 m/s (4x as fast through water,
14x as fast through steel)
reflection - CORRECT ANSWER - is an echo or a reverberation
reverberation - CORRECT ANSWER - often in a small room, 17m or less, reverbs can
mask high frequencies
echo - CORRECT ANSWER - heard and perceived later than original sound (more than
1/10s after)
absorption - CORRECT ANSWER - aborbs sound. can improve environments w/
reflection or reverb. better in warmth and moist
diffraction - CORRECT ANSWER - sharpness in the change in direction of sound,
bending. high diffraction=bigger wavelengths (low freq)
, refraction - CORRECT ANSWER - sound passes through one medium to another, change
in speed and wavelength
infrasound - CORRECT ANSWER - below audible range of 20 Hz
ultrasound - CORRECT ANSWER - above audible range of 20K Hz
octave - CORRECT ANSWER - anytime the frequency doubles. f(2) = on octave; f(3)=
two octaves
faintest sound a human can hear - CORRECT ANSWER - 10 ^ -16 watts/cm^2 and
pressure of .0002 dynes/cm^2
threshold of pain - CORRECT ANSWER - 1000 dynes/cm^2
when SPL levels double how many db levels increase? - CORRECT ANSWER - 6 db
db HL expresses: - CORRECT ANSWER - threshold levels
db SPL expresses: - CORRECT ANSWER - voices or environmental sounds
pinna function: - CORRECT ANSWER - gather sound, aid in localization, enahnce high
freq bw 2k-5k hz
aperture - CORRECT ANSWER - entrance to canal, first bend
isthmus - CORRECT ANSWER - narrowing of canal
