Hearing Aid Dispenser Written Exam Questions With
100% Correct Answers To Score A+
db loss of a perforation of TM
10-15db loss
procedure done to fix perforation
tympanoplasty or myringoplasty
monomeric spots
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
2.3-2.9cm in length, .7cm in diameters
pars tensa
lower 4/5 of TM and tight
pars flaccida
upper 1/5 of TM and flaccid
otis externa
"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
masses of tissue that grow outward from a surface
cholesteatoma
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
result of ear surgery. often have no ear drum or ossicular chain. need approval of
physician before fitting
tympanosclerosis
white, chalky calcium deposits caused by degeneration of tissue on eardrum, thicking
and scarring from peforations and infections
epitympanic cavity
attic of middle ear. allows air into mastoid cells of temporal bone. branches several
nerves
incudotapedial junction
top of incus to head of stapes
annular ligament
footplate of stapes that is held in the oval window
speed of sound
700mph or 340 m/s (4x as fast through water, 14x as fast through steel)
reflection
is an echo or a reverberation
reverberation
often in a small room, 17m or less, reverbs can mask high frequencies
echo
, heard and perceived later than original sound (more than 1/10s after)
absorption
aborbs sound. can improve environments w/ reflection or reverb. better in warmth and
moist
diffraction
sharpness in the change in direction of sound, bending. high diffraction=bigger
wavelengths (low freq)
refraction
sound passes through one medium to another, change in speed and wavelength
infrasound
below audible range of 20 Hz
ultrasound
above audible range of 20K Hz
octave
anytime the frequency doubles. f(2) = on octave; f(3)= two octaves
faintest sound a human can hear
10 ^ -16 watts/cm^2 and pressure of .0002 dynes/cm^2
threshold of pain
1000 dynes/cm^2
when SPL levels double how many db levels increase?
6 db
db HL expresses:
threshold levels
db SPL expresses:
voices or environmental sounds
pinna function:
gather sound, aid in localization, enahnce high freq bw 2k-5k hz
aperture
entrance to canal, first bend
isthmus
narrowing of canal
resonance frequency
between 3k-4k (or 2k-5k in other studies) range, natural boost of 10db, when combined
w/ high freq enhancement of the pinna - 15-20 db increase around 2700 hz
stenosis
narrowing of ear canal
atresia
absense of an ear canal
microtia
smaller than normal pinna
anotia
absence of one or both external ears
oval window
at footplate of stapes
round window
100% Correct Answers To Score A+
db loss of a perforation of TM
10-15db loss
procedure done to fix perforation
tympanoplasty or myringoplasty
monomeric spots
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
2.3-2.9cm in length, .7cm in diameters
pars tensa
lower 4/5 of TM and tight
pars flaccida
upper 1/5 of TM and flaccid
otis externa
"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
masses of tissue that grow outward from a surface
cholesteatoma
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
result of ear surgery. often have no ear drum or ossicular chain. need approval of
physician before fitting
tympanosclerosis
white, chalky calcium deposits caused by degeneration of tissue on eardrum, thicking
and scarring from peforations and infections
epitympanic cavity
attic of middle ear. allows air into mastoid cells of temporal bone. branches several
nerves
incudotapedial junction
top of incus to head of stapes
annular ligament
footplate of stapes that is held in the oval window
speed of sound
700mph or 340 m/s (4x as fast through water, 14x as fast through steel)
reflection
is an echo or a reverberation
reverberation
often in a small room, 17m or less, reverbs can mask high frequencies
echo
, heard and perceived later than original sound (more than 1/10s after)
absorption
aborbs sound. can improve environments w/ reflection or reverb. better in warmth and
moist
diffraction
sharpness in the change in direction of sound, bending. high diffraction=bigger
wavelengths (low freq)
refraction
sound passes through one medium to another, change in speed and wavelength
infrasound
below audible range of 20 Hz
ultrasound
above audible range of 20K Hz
octave
anytime the frequency doubles. f(2) = on octave; f(3)= two octaves
faintest sound a human can hear
10 ^ -16 watts/cm^2 and pressure of .0002 dynes/cm^2
threshold of pain
1000 dynes/cm^2
when SPL levels double how many db levels increase?
6 db
db HL expresses:
threshold levels
db SPL expresses:
voices or environmental sounds
pinna function:
gather sound, aid in localization, enahnce high freq bw 2k-5k hz
aperture
entrance to canal, first bend
isthmus
narrowing of canal
resonance frequency
between 3k-4k (or 2k-5k in other studies) range, natural boost of 10db, when combined
w/ high freq enhancement of the pinna - 15-20 db increase around 2700 hz
stenosis
narrowing of ear canal
atresia
absense of an ear canal
microtia
smaller than normal pinna
anotia
absence of one or both external ears
oval window
at footplate of stapes
round window
