Hearing Aid Dispenser Written Exam 2026–2027
Complete Study Guide, Practice Questions &
Licensing Exam Prep
db loss of a perforation of TM - correct answers -10-15db loss
procedure done to fix perforation - correct answers -tympanoplasty or myringoplasty
monomeric spots - correct answers -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 answers -2.3-2.9cm in length, .7cm in diameters
pars tensa - correct answers -lower 4/5 of TM and tight
pars flaccida - correct answers -upper 1/5 of TM and flaccid
otis externa - correct answers -"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 answers -masses of tissue that grow outward from a surface
cholesteatoma - correct answers -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.
1
,enlarged canal - correct answers -result of ear surgery. often have no ear drum or ossicular chain. need
approval of physician before fitting
tympanosclerosis - correct answers -white, chalky calcium deposits caused by degeneration of tissue on
eardrum, thicking and scarring from peforations and infections
epitympanic cavity - correct answers -attic of middle ear. allows air into mastoid cells of temporal bone.
branches several nerves
incudotapedial junction - correct answers -top of incus to head of stapes
annular ligament - correct answers -footplate of stapes that is held in the oval window
speed of sound - correct answers -700mph or 340 m/s (4x as fast through water, 14x as fast through
steel)
reflection - correct answers -is an echo or a reverberation
reverberation - correct answers -often in a small room, 17m or less, reverbs can mask high frequencies
echo - correct answers -heard and perceived later than original sound (more than 1/10s after)
absorption - correct answers -aborbs sound. can improve environments w/ reflection or reverb. better
in warmth and moist
2
, diffraction - correct answers -sharpness in the change in direction of sound, bending. high
diffraction=bigger wavelengths (low freq)
refraction - correct answers -sound passes through one medium to another, change in speed and
wavelength
infrasound - correct answers -below audible range of 20 Hz
ultrasound - correct answers -above audible range of 20K Hz
octave - correct answers -anytime the frequency doubles. f(2) = on octave; f(3)= two octaves
faintest sound a human can hear - correct answers -10 ^ -16 watts/cm^2 and pressure of .0002
dynes/cm^2
threshold of pain - correct answers -1000 dynes/cm^2
when SPL levels double how many db levels increase? - correct answers -6 db
db HL expresses: - correct answers -threshold levels
db SPL expresses: - correct answers -voices or environmental sounds
3
Complete Study Guide, Practice Questions &
Licensing Exam Prep
db loss of a perforation of TM - correct answers -10-15db loss
procedure done to fix perforation - correct answers -tympanoplasty or myringoplasty
monomeric spots - correct answers -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 answers -2.3-2.9cm in length, .7cm in diameters
pars tensa - correct answers -lower 4/5 of TM and tight
pars flaccida - correct answers -upper 1/5 of TM and flaccid
otis externa - correct answers -"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 answers -masses of tissue that grow outward from a surface
cholesteatoma - correct answers -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.
1
,enlarged canal - correct answers -result of ear surgery. often have no ear drum or ossicular chain. need
approval of physician before fitting
tympanosclerosis - correct answers -white, chalky calcium deposits caused by degeneration of tissue on
eardrum, thicking and scarring from peforations and infections
epitympanic cavity - correct answers -attic of middle ear. allows air into mastoid cells of temporal bone.
branches several nerves
incudotapedial junction - correct answers -top of incus to head of stapes
annular ligament - correct answers -footplate of stapes that is held in the oval window
speed of sound - correct answers -700mph or 340 m/s (4x as fast through water, 14x as fast through
steel)
reflection - correct answers -is an echo or a reverberation
reverberation - correct answers -often in a small room, 17m or less, reverbs can mask high frequencies
echo - correct answers -heard and perceived later than original sound (more than 1/10s after)
absorption - correct answers -aborbs sound. can improve environments w/ reflection or reverb. better
in warmth and moist
2
, diffraction - correct answers -sharpness in the change in direction of sound, bending. high
diffraction=bigger wavelengths (low freq)
refraction - correct answers -sound passes through one medium to another, change in speed and
wavelength
infrasound - correct answers -below audible range of 20 Hz
ultrasound - correct answers -above audible range of 20K Hz
octave - correct answers -anytime the frequency doubles. f(2) = on octave; f(3)= two octaves
faintest sound a human can hear - correct answers -10 ^ -16 watts/cm^2 and pressure of .0002
dynes/cm^2
threshold of pain - correct answers -1000 dynes/cm^2
when SPL levels double how many db levels increase? - correct answers -6 db
db HL expresses: - correct answers -threshold levels
db SPL expresses: - correct answers -voices or environmental sounds
3
