Hearing Aid Dispenser Written Exam
Questions and Answers (Graded A)
db loss of a perforation of TM - ANSWER - 10-15db loss
procedure done to fix perforation - ANSWER - tympanoplasty or myringoplasty
monomeric spots - 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 - ANSWER - 2.3-2.9cm in length, .7cm in diameters
pars tensa - ANSWER - lower 4/5 of TM and tight
pars flaccida - ANSWER - upper 1/5 of TM and flaccid
otis externa - 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 - ANSWER - masses of tissue that grow outward from a surface
cholesteatoma - 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.
epitympanic cavity - ANSWER - attic of middle ear. allows air into mastoid cells of temporal
bone. branches several nerves
incudotapedial junction - ANSWER - top of incus to head of stapes
,annular ligament - ANSWER - footplate of stapes that is held in the oval window
enlarged canal - ANSWER - result of ear surgery. often have no ear drum or ossicular chain.
need approval of physician before fitting
tympanosclerosis - ANSWER - white, chalky calcium deposits caused by degeneration of tissue
on eardrum, thicking and scarring from peforations and infections
acoustic reflex - ANSWER - tensor tympani (muscle on malleus) and the stapedius muscle
contract to prevent damaging intensities of loud sounds
otitis media aka OM - ANSWER - fluid in middle ear space, most common, fluid can be infected
non-supportive OM - ANSWER - w/ no infection
suppurative OM -3 classifications - ANSWER - 1. acute - more severe w/ short duration and
onset. 2. chronic - recurring infection. 3. adhesive - fluid becomes thick and sticky
procedure to treat OM - ANSWER - PE tube
speed of sound - ANSWER - 700mph or 340 m/s (4x as fast through water, 14x as fast through
steel)
reflection - ANSWER - is an echo or a reverberation
reverberation - ANSWER - often in a small room, 17m or less, reverbs can mask high
frequencies
echo - ANSWER - heard and perceived later than original sound (more than 1/10s after)
, absorption - ANSWER - aborbs sound. can improve environments w/ reflection or reverb. better
in warmth and moist
diffraction - ANSWER - sharpness in the change in direction of sound, bending. high
diffraction=bigger wavelengths (low freq)
refraction - ANSWER - sound passes through one medium to another, change in speed and
wavelength
infrasound - ANSWER - below audible range of 20 Hz
ultrasound - ANSWER - above audible range of 20K Hz
octave - ANSWER - anytime the frequency doubles. f(2) = on octave; f(3)= two octaves
faintest sound a human can hear - ANSWER - 10 ^ -16 watts/cm^2 and pressure of .0002
dynes/cm^2
threshold of pain - ANSWER - 1000 dynes/cm^2
when SPL levels double how many db levels increase? - ANSWER - 6 db
db HL expresses: - ANSWER - threshold levels
db SPL expresses: - ANSWER - voices or environmental sounds
pinna function: - ANSWER - gather sound, aid in localization, enahnce high freq bw 2k-5k hz
aperture - ANSWER - entrance to canal, first bend
isthmus - ANSWER - narrowing of canal
Questions and Answers (Graded A)
db loss of a perforation of TM - ANSWER - 10-15db loss
procedure done to fix perforation - ANSWER - tympanoplasty or myringoplasty
monomeric spots - 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 - ANSWER - 2.3-2.9cm in length, .7cm in diameters
pars tensa - ANSWER - lower 4/5 of TM and tight
pars flaccida - ANSWER - upper 1/5 of TM and flaccid
otis externa - 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 - ANSWER - masses of tissue that grow outward from a surface
cholesteatoma - 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.
epitympanic cavity - ANSWER - attic of middle ear. allows air into mastoid cells of temporal
bone. branches several nerves
incudotapedial junction - ANSWER - top of incus to head of stapes
,annular ligament - ANSWER - footplate of stapes that is held in the oval window
enlarged canal - ANSWER - result of ear surgery. often have no ear drum or ossicular chain.
need approval of physician before fitting
tympanosclerosis - ANSWER - white, chalky calcium deposits caused by degeneration of tissue
on eardrum, thicking and scarring from peforations and infections
acoustic reflex - ANSWER - tensor tympani (muscle on malleus) and the stapedius muscle
contract to prevent damaging intensities of loud sounds
otitis media aka OM - ANSWER - fluid in middle ear space, most common, fluid can be infected
non-supportive OM - ANSWER - w/ no infection
suppurative OM -3 classifications - ANSWER - 1. acute - more severe w/ short duration and
onset. 2. chronic - recurring infection. 3. adhesive - fluid becomes thick and sticky
procedure to treat OM - ANSWER - PE tube
speed of sound - ANSWER - 700mph or 340 m/s (4x as fast through water, 14x as fast through
steel)
reflection - ANSWER - is an echo or a reverberation
reverberation - ANSWER - often in a small room, 17m or less, reverbs can mask high
frequencies
echo - ANSWER - heard and perceived later than original sound (more than 1/10s after)
, absorption - ANSWER - aborbs sound. can improve environments w/ reflection or reverb. better
in warmth and moist
diffraction - ANSWER - sharpness in the change in direction of sound, bending. high
diffraction=bigger wavelengths (low freq)
refraction - ANSWER - sound passes through one medium to another, change in speed and
wavelength
infrasound - ANSWER - below audible range of 20 Hz
ultrasound - ANSWER - above audible range of 20K Hz
octave - ANSWER - anytime the frequency doubles. f(2) = on octave; f(3)= two octaves
faintest sound a human can hear - ANSWER - 10 ^ -16 watts/cm^2 and pressure of .0002
dynes/cm^2
threshold of pain - ANSWER - 1000 dynes/cm^2
when SPL levels double how many db levels increase? - ANSWER - 6 db
db HL expresses: - ANSWER - threshold levels
db SPL expresses: - ANSWER - voices or environmental sounds
pinna function: - ANSWER - gather sound, aid in localization, enahnce high freq bw 2k-5k hz
aperture - ANSWER - entrance to canal, first bend
isthmus - ANSWER - narrowing of canal
