Hearing Aid Dispenser License Questions with Verified Answers
Question 1: What is the dB loss of a perforation of the
tympanic membrane (TM)?
CORRECT ANSWER: 10-15 dB loss
Question 2: What procedure is done to fix a perforation of the
tympanic membrane?
CORRECT ANSWER : Tympanoplasty or myringoplasty
Question 3: What are monomeric spots?
CORRECT ANSWER : Looks like a hole in TM, but reflects
light like a mirror. Holes that have healed. Aka "mirror membranes"
Question 4: What are the average dimensions of an adult
eardrum?
CORRECT ANSWER : 2.3-2.9 cm in length, 0.7 cm in
diameter
Question 5: What is the pars tensa?
CORRECT ANSWER : Lower 4/5 of TM and tight
Question 6: What is the pars flaccida?
CORRECT ANSWER : Upper 1/5 of TM and flaccid
Question 7: What is otitis 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
Question 8: What are polyps?
CORRECT ANSWER : Masses of tissue that grow outward
from a surface
Question 9: What is a cholesteatoma?
CORRECT ANSWER : Non-cancerous tumor in the middle
ear. Odorous discharge. Sometimes perforates upper TM.Invasion of skin into the middle ear - sac of concentric rings
of protein. Causes conductive loss. Most dangerous pathology.
Question 10: What is an enlarged canal?
CORRECT ANSWER : Result of ear surgery. Often have no
ear drum or ossicular chain. Need approval of physician before fitting
Question 11: What is tympanosclerosis?
CORRECT ANSWER : White, chalky calcium deposits
caused by degeneration of tissue on eardrum, thickening and scarring from perforations and infections
Question 12: What is the epitympanic cavity?
CORRECT ANSWER : Attic of middle ear. Allows air into
mastoid cells of temporal bone. Branches several nerves
Question 13: What is the incudostapedial junction?
CORRECT ANSWER : Top of incus to head of stapes
Question 14: What is the annular ligament?
CORRECT ANSWER : Footplate of stapes that is held in the
oval window
Question 15: What is the speed of sound?
CORRECT ANSWER : 700 mph or 340 m/s (4x as fast
through water, 14x as fast through steel)
Question 16: What is reflection?
CORRECT ANSWER : Is an echo or a reverberation
Question 17: What is reverberation?
CORRECT ANSWER : Often in a small room, 17m or less,
reverbs can mask high frequencies
Question 18: What is an echo?
CORRECT ANSWER : Heard and perceived later than
original sound (more than 1/10s after)