Hearing Aid Dispenser Written Exam Questions With 100% Correct Answers To Score A+

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 hydraulic energy discharging membrane - pressure release window for cochlea acoustic reflex tensor tympani (muscle on malleus) and the stapedius muscle contract to prevent damaging intensities of loud sounds otitis media aka OM fluid in middle ear space, most common, fluid can be infected non-supportive OM w/ no infection suppurative OM -3 classifications 1. acute - more severe w/ short duration and onset. 2. chronic - recurring infection. 3. adhesive - fluid becomes thick and sticky procedure to treat OM PE tube otosclerosis spongy growth on stapes, causing fixation and progressive loss. Audiometrically will have a notch at 2k hz called Carharts Notch (cond component across board except at 2k). procedure: stapedectomy to remove and replace w/ prosthesis barotrauma caused by sudden change in air pressure (eustachian tube dysfunction). may result in fistula fistula abnormal opening b/w middle and inner ear. can cause SN loss if hair cells damaged by loss of fluid mastoiditis infection of mastoid bone. risk of meningitis. procedure: mastoidectomy or antibiotics stiffness effect conductive component in low freq * eustachian tube dysfunction mass effect conductive component in high freq * otitis media perilymph same as cerebral-spinal fluid. found in scala vestibula and scala tympani endolymph manufactured in cochlea, slightly diff polarity than perilymph. found in scala media inner hair cells about 3k-4k / ear. they are afferent - SEND info TO the brain outer hair cells 3-4 rows, about 12k-15k /ear (12k was answer on the practice test). they are efferent - RECEIVE info FROM the brain. they amplify soft sounds in the cochlea base of cochlea respond to: high freq sounds apex of cochlea respond to: low freq sounds hyperacusis abnormally acute hearing due to heightened irritability of the sensory and/or neural mechanisms. bothered by moderate or even soft sounds acoustic neuroma tumor on auditory nerve. can be life-threatening. symptoms: large, unexpected AN asymmetries, WR poorer than expected, recent onset of unilateral tinnitus, dizziness. tests for acoustic neuroma PIPB (rollover test), acoustic reflex delay, tone decay, ABR, MRI labyrinthitis inflammation of the inner ear, involving both vestibular & auditory portions meniere's disease aka endolymphatic hydrops build up of fluids in the scala media, too much production of endolymph or absorbed too slowly resulting in pressure that damages the organ of corti. most apparent symptom: vertigo auditory neuropathy distorted speech. aud deprivation telephone-type electronic h.a 1k-1800 hz, 10-15 db gain w/ carbon granule microphone (heavy static). 1892 vacuume tube crystal microphone (high impedence, failed at humidity and temp increases; fragile). 1907, emerged in the 20s-30s miniature vacuum tube wearing h.a. 1938-50s Year of first, 1-piece aid: 1944 transitor eva on head via glasses or post auricle aids. 1947-50s ITE custom transitor using magnetic microphones (sufficient in speech freq and durable) 1964, omnidirectional ceramic microphone improves crystal but had very high impedence, omnidirectional FET microphone transformed the impedence and improved sensitivity, extended the freq range in the lows to 10 hz, withstood heat and humidity better electret microphone used in almost all aids today! integrated circuit aka IC various components all populated into a tiny wafer of silicone. helps miniaturize. electrical energy from microphone is amplified and modified by the IC microphone function: takes acoustical energy (waves) and transduces it to electrical energy receiver function: tranduces the electrical energy from the microphone and IC and transduces it back to acoustical energy conductors allow flow of electrons (current). the greater the flow of the current in HA, the greater the vol or strength. (the battery is a conductor. measured in V) semi-conductors