Hearing Aid Dispenser Written Exam Study Guide with Complete Solutions 2024/2025 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 1 / 3
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 2 / 3
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 resonance frequency - Correct Answer 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 - Correct Answer narrowing of ear canal atresia - Correct Answer absense of an ear canal microtia - Correct Answer smaller than normal pinna anotia - Correct Answer absence of one or both external ears oval window - Correct Answer at footplate of stapes round window - Correct Answer hydraulic energy discharging membrane - pressure release window for cochlea acoustic reflex - Correct Answer tensor tympani (muscle on malleus) and the stapedius muscle contract to prevent damaging intensities of loud sounds otitis media aka OM - Correct Answer fluid in middle ear space, most common, fluid can be infected
- / 3