Hearing Aid Dispenser's Written Exam with 100% Correct Solutions

db loss of a perforation of TM - ANS 10-15db loss procedure done to fix perforation - ANS tympanoplasty or myringoplasty monomeric spots - ANS 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 - ANS 2.3-2.9cm in length, .7cm in diameters pars tensa - ANS lower 4/5 of TM and tight pars flaccida - ANS upper 1/5 of TM and flaccid otis externa - ANS "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 - ANS masses of tissue that grow outward from a surface cholesteatoma - ANS 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 - ANS result of ear surgery. often have no ear drum or ossicular chain. need approval of physician before fitting tympanosclerosis - ANS white, chalky calcium deposits caused by degeneration of tissue on eardrum, thicking and scarring from peforations and infections epitympanic cavity - ANS attic of middle ear. allows air into mastoid cells of temporal bone. branches several nerves incudotapedial junction - ANS top of incus to head of stapes annular ligament - ANS footplate of stapes that is held in the oval window speed of sound - ANS 700mph or 340 m/s (4x as fast through water, 14x as fast through steel) reflection - ANS is an echo or a reverberation reverberation - ANS often in a small room, 17m or less, reverbs can mask high frequencies echo - ANS heard and perceived later than original sound (more than 1/10s after) absorption - ANS aborbs sound. can improve environments w/ reflection or reverb. better in warmth and moist diffraction - ANS sharpness in the change in direction of sound, bending. high diffraction=bigger wavelengths (low freq) refraction - ANS sound passes through one medium to another, change in speed and wavelength infrasound - ANS below audible range of 20 Hz ultrasound - ANS above audible range of 20K Hz octave - ANS anytime the frequency doubles. f(2) = on octave; f(3)= two octaves faintest sound a human can hear - ANS 10 ^ -16 watts/cm^2 and pressure of .0002 dynes/cm^2 threshold of pain - ANS 1000 dynes/cm^2 when SPL levels double how many db levels increase? - ANS 6 db db HL expresses: - ANS threshold levels db SPL expresses: - ANS voices or environmental sounds pinna function: - ANS gather sound, aid in localization, enahnce high freq bw 2k-5k hz aperture - ANS entrance to canal, first bend isthmus - ANS narrowing of canal resonance frequency - ANS 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 - ANS narrowing of ear canal atresia - ANS absense of an ear canal microtia - ANS smaller than normal pinna anotia - ANS absence of one or both external ears oval window - ANS at footplate of stapes round window - ANS hydraulic energy discharging membrane - pressure release window for cochlea acoustic reflex - ANS tensor tympani (muscle on malleus) and the stapedius muscle contract to prevent damaging intensities of loud sounds otitis media aka OM - ANS fluid in middle ear space, most common, fluid can be infected non-supportive OM - ANS w/ no infection suppurative OM -3 classifications - ANS 1. acute - more severe w/ short duration and onset. 2. chronic - recurring infection. 3. adhesive - fluid becomes thick and sticky procedure to treat OM - ANS PE tube otosclerosis - ANS 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 - ANS caused by sudden change in air pressure (eustachian tube dysfunction). may result in fistula fistula - ANS abnormal opening b/w middle and inner ear. can cause SN loss if hair cells damaged by loss of fluid mastoiditis - ANS infection of mastoid bone. risk of meningitis. procedure: mastoidectomy or antibiotics stiffness effect - ANS conductive component in low freq * eustachian tube dysfunction mass effect - ANS conductive component in high freq * otitis media perilymph - ANS same as cerebral-spinal fluid. found in scala vestibula and scala tympani endolymph - ANS manufactured in cochlea, slightly diff polarity than perilymph. found in scala media inner hair cells - ANS about 3k-4k / ear. they are afferent - SEND info TO the brain outer hair cells - ANS 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: - ANS high freq sounds apex of cochlea respond to: - ANS low freq sounds hyperacusis - ANS abnormally acute hearing due to heightened irritability of the sensory and/or neural mechanisms. bothered by moderate or even soft sounds acoustic neuroma - ANS 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 - ANS PIPB (rollover test), acoustic reflex delay, tone decay, ABR, MRI labyrinthitis - ANS inflammation of the inner ear, involving both vestibular & auditory portions meniere's disease aka endolymphatic hydrops - ANS 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 - ANS distorted speech. aud deprivation telephone-type electronic h.a - ANS 1k-1800 hz, 10-15 db gain w/ carbon granule microphone (heavy static). 1892 vacuume tube - ANS crystal microphone (high impedence, failed at humidity and temp increases; fragile). 1907, emerged in the 20s-30s miniature vacuum tube - ANS wearing h.a. 1938-50s Year of first, 1-piece aid: - ANS 1944 transitor eva - ANS on head via glasses or post auricle aids. 1947-50s ITE custom - ANS transitor using magnetic microphones (sufficient in speech freq and durable) 1964, omnidirectional ceramic microphone - ANS improves crystal but had very high impedence, omnidirectional FET microphone - ANS transformed the impedence and improved sensitivity, extended the freq range in the lows to 10 hz, withstood heat and humidity better electret microphone - ANS used in almost all aids today! integrated circuit aka IC - ANS 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: - ANS takes acoustical energy (waves) and transduces it to electrical energy receiver function: - ANS tranduces the electrical energy from the microphone and IC and transduces it back to acoustical energy conductors - ANS 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 - ANS act as a conductor under certain conditions. when heat, light or an electric field is applied to the outer shell, the electrons start flowing resistors / insulators - ANS limits the flow of electrons. measured in ohms (ex: tubing). insulators = high resistors current - ANS voltage/resistance OR sound/pressure capacitor - ANS impede low freq and pass the highs (like resistors, also measure in ohms) inductor - ANS impede the high freq and pass the lows EX: telecoil (like resistors, also measure in ohms) transitor - ANS amplifier. also a semi-conductor. acts like a spring board for current flow. years of first digital hearing aids: - ANS 80s (then improved in 1996) omnidirectional microphone: - ANS pick up sound equally from all directions. [directionality can be accomplished by a 2-phased matched omnidirectional microphones. works like a directional microphone] directional microphone - ANS 2 ports that pick up sound, picks up sounds to the front of the instrument - better focus automatic directionality - ANS HA doesnt need to be manually adjusted. The environmental classifier determines when it is directional or omnidirectional automatically fixed directional microphone - ANS directional setting in HA maintains a stationary polar pattern, typically hypercardioid adaptive directionality - ANS environmental classifier will change the polar plot to best pick up the speech signals it detects. adapts to its environment and changes polar pattern appropriately multichannel adaptive - ANS directional system recognized noise in several diff frequency regions. you can adjust settings independently in separate frequencies. BILL circuit (ASP circuit) - ANS "bass increase at low levels", would provide and increase in the low freq. when in quiet environment. In noise and loud environment, reduce low freq. amplification TILL circuit (ASP circuit) - ANS "treble increase at low levels", would provide increase in high freq. when in quiet environment. In noisy environment, reduce high freq. PILL circuit (ASP circuit) - ANS "programmable increase at low levels" combo of both the BILL and TILL circuits. multi-band processor that can process signals independently WDRC - wide dynamic range compression - ANS not limited to high or low freq, can divide the audio spectrum into multiple bands & each band has its own compression ratio. (most HAs today) Peak clipping technique - ANS applied if sounds were too sharp, "clipped" off the output response, this resulted in distortion horn tubes - ANS for max high freq. emphasis most common horn tube - ANS libby horn what is a stenger used for / what is the stenger test? - ANS specific test to rule out malingering / non-organic test that sends out two different intensities of the same frequency in both ears the masking noise used for AC masking - ANS narrow-band noise masking noise used for speech signals - ANS speech noise white noise definition - ANS signal w/ all freq at the same time; above 1k hz @ 3db octave name for the bracketing technique in testing - ANS hughson/westlake technique agreement between pta and srt - ANS plus or minus 10db tests you can do in place of srt - ANS sdt (speech detection threshold) or sat (speech awareness test). pt indicated that they just heard something, but do not need to repeat the word back correctly. should be w/in 20db of pta how to mask for SRT - ANS begin speech noise masking in the better ear at its srt +10db. then begin testing poorer ear w/ spondee words. plateau method how to mask for WR - ANS mask when the presentation level in one ear - IA is greater than or equal to the srt of the other ear. the masking level in the NTE is the presentation level of the TE - 20db (or 30db if mask level is too loud to them) relationship of speech UCL from db HL to db SPL - ANS add 20 db to go to SPL what is the HA matrix ratio - ANS max power output (MPO) / gain 1/2 gain rule - ANS divide the srt by 2 and add 10 db for reserve. ex: srt=40 ; 40/2 = 20 + 10 = 30. Prescribed gain would be 30 db positive pressure TM moves ______ - ANS TM goes into middle ear. negative pressure TM moves ______ - ANS TM goes into canal normal pressure values of TM (the force it takes) - ANS -150 to +25 daPa normal compliance values of TM (how much it moves) - ANS .3 to 1.4 mmho do not perform tympanometry - ANS ear surgery, blood or discharge, pain, otitis externa type A tympanogram - ANS normal pressure and compliance type As tympanogram - ANS normal pressure, low compliance. - otosclerosis (stiff TM bc bones have calcification). need less gain type Ad tympanogram - ANS normal pressure, high compliance - discontinuity (bones separated or broken). need more gain type B tympanogram - ANS otitis media w/ effusion (ear canal vol around 2 on scale), or cerumen impactment (ear canal vol around 1 on scale) (earn canal vol at 5 if perforation of ear drum) type C tympanogram - ANS not normal pressure (offset to negative); eustachian tube dysfunction (can come w/ colds or flying and temporary) can you fit HAs with any abnormal tympanogram? - ANS yes effect of narrowing the end of a horn (reverse horn) - ANS reduces the high freq's effect of belling the end of a horn - ANS increases the high freq's How much gain in a RIC fitting? - ANS 20db what is an output transducer in a hearing aid? - ANS the receiver what freq cannot be calculated for in a high freq avg? - ANS 2k Hz least common type of vent - ANS internal vent what is a CNC word list and what is it used for - ANS monosyllabic words composed of three phonemes for SRT testing class 1 programmable hearing aid - ANS single channel w/ single memory class 2 programmable hearing aid - ANS single channel w/ multiple memory class 3 programmable hearing aid - ANS multiple channel w/ single memory class 4 programmable hearing aid - ANS multiple channel w/ multiple memory most advanced type of memory in hearing aids today - ANS electrically erasable programmable read-only memory Benefits of a digital amplifier over analog - ANS less internal noise and distortion, greater shaping flexibility, the ability to perform noise suppression and feedback management relationship between A/D and D/A converter - ANS A/D (analog-to-digital) changes the incoming electrical waveform into strings of mathematical bits. After processing, the digital waveform is changed back in to an analog waveform via a D/A converter linear amplification - ANS constant gain on an input/output graph, same ratio non-linear amplification - ANS typically applies reduced gain for increased inputs class A amplifier - ANS simple and inefficient, current flows through it even when there is no input. output limitation is accomplished by "peak clipping" even as moderate inputs = distortion class B amplifier - ANS combines two class A amplifier w/ switched polarities. "pushes" the compression phase and "pulls" the rarefaction phase. can produce more gain and output than class A but inefficient, large, and more battery consumption class D amplifier - ANS aka "swiching amplifier" - designed to decrease drain on the battery (current only flows when there is input) while providing close to class B power levels. clearer sound quality w/ no peak clipping and most efficient input compression - ANS the compression kneepoint (CK) will remain the same at all times. changes in the volume control will affect both the gain and maximum output output compression - ANS when the volume control is adjusted both the gain and the CK will change, but the maximum output will remain constant wide dynamic range compression WDRC - ANS amplify the full range of speech within the users reduced dynamic range or area of processing. makes for inaudible and soft sounds more audible and better understanding % difference in monaural WR scores that require a medical referral - ANS 20% binaural degradation - ANS when the binaural WR score is lower than the better ear WR score. medical referral required maximum OSPL output formula - ANS speech UCL + 20db typically; or pure tone LDL between 2k and 3k + 10db verification definition - ANS making sure hearing aid performance meets a certain fitting standard/criteria validation definition - ANS about determining how much benefit the patient is receiving from the hearing aids Content included in the NOAH fitting software - ANS multiple hearing aid fitting system, data base, office management system components of the integrated circuit (IC) - ANS capacitor, transitor, resistor *** just remember "ctr" kinda like "cpr" ? if we increase 10 db SPL, how much loudness can be increased in our perception? - ANS 2x louder least favorable slope of h. loss shape - ANS steep falling in low freq head shadow effect in a non-aural fitting would attenuate what frequencies the most? - ANS high freq's in general, how much wind noise is decreased in the CIC fitting? - ANS 26 db what is the most complex sound in hearing industry? - ANS human voice intensity shift in central masking - ANS 5 db normal intensity level of MCL in average people? - ANS 65 db SPL main purpose of tympanometry - ANS to check the compliance of the eardrum the elastic medium in sound - ANS air weber test (tuning fork) - ANS tuning fork test that checks whether the bone conductive tone is heard in the right, left, or both ears. 512 hz tuning fork is placed on the patient's forehead. If the sound lateralizes (is louder on one side than the other), the patient may have either an ipsilateral conductive hearing loss or a contralateral sensorineural hearing loss from where the sound was heard loudest. rhine test (tuning fork) - ANS compares the sensitivity by bone conduction to air conduction through the mastoid. primarily for evaluating loss of hearing in one ear bing test (tuning fork) - ANS fork is struck and placed on the patient's mastoid tip. the examiner alternately occludes the patient's external meatus. if pt has normal hearing or a sensorineural loss, they'll notice a change in intensity with occlusion. If pt has a conductive hearing loss, he or she will notice no change. schwabach test (tuning fork) - ANS compares the patient's bone conduction to that of the examiner's. If the pt stops hearing before the examiner, this suggests a sensorineural loss. If the pt hears it longer than the examiner, this suggests a conductive loss. contingent on the examiner having normal hearing. WIPI test (for children) - ANS WR test for children that use pictures to determine the test score what impedance is independent from the frequency? - ANS resistance (hint capacitors and inductors impede either a high or low freq) components of an acoustic immittance tester (tympanometry) - ANS balance meter, potentionmeter, manometer in an acoustic reflex test, what type of hearing loss or lesion is present if the acoustic reflex is lower than the usual sensation level? - ANS cochlear lesion is there any static compliance w/ otosclerosis? - ANS yes, average static compliance what material is used for SDT? - ANS cold running speech (practice test answer..) unit of loudness measurement - ANS phon if we want to perceive 2x loudness of sound, how much sound intensity do we need? - ANS 10 db phonemic regression - ANS loss of understanding due to presbycusis number of turns of the cochlear duct - ANS 2.5 intermodulation distortion - ANS in the hearing aid. occurs when two frequencies are presented simultaneously to a hearing aid and the output contains one or more frequencies that are related to the sum and difference of the two input frequencies. harmonic distortion - ANS in the hearing aid. occurs when a single frequency is presented to the input of a hearing aid and the output contains the original frequency plus additional undesired frequencies that are harmonically related to the original frequency. cause of harmonic distortion - ANS mechanical stress in hearing aid transient distortion - ANS occurs when a large abrupt change occurs in the level of the input sound and creates IMD products in the output. not generally perceived by the wearer unit measurement of pitch - ANS Mel biggest concern when using dampers - ANS moisture build up formula for the need to mask in air conduction test - ANS ACte - IA is greater than or equal to the BCnte false negative response in testing - ANS patient does not respond when they have heard the test false positive response in testing - ANS patient response when no sound is presented what is the IA for supra aural headphone for ac test? - ANS average 55db (minimal 40db) automatic gain control definition - ANS control the sound intensity associated w/ feedback circuit insertion gain - ANS the SPL gain by the hearing aid measured at the eardrum w/ a probe microphone noise induced hearing loss in males is _______ than in females - ANS more severe and more frequent autophony - ANS or tympanophony is the unusually loud hearing of a person's own voice. possible cause: the occlusion effect what are some possible causes for meniere's disease? - ANS infection, degeneration of middle ear, blow to the head (aside from the excess endolymph present as noted in another card) unit of power - ANS watt common finding w/ conductive loss: high or low UCL? - ANS high most critical precaution for a first time hearing aid user - ANS you do not increase the output more than MCL level in hearing aids, what component produces the most noise? - ANS microphone what hearing loss would have the greatest risk of over masking? - ANS unilateral conductive loss formula for effective masking in bc testing - ANS EM = ACnte + OE Rollover ratio in the WRT test - ANS rollover ratio = pb max - (pb min/pb max) helicotrema - ANS narrowest pass-way between scala vestibule and scala tympani advantage of testing the bone conduction threshold at the forehead - ANS improve test reliability what is the most-likely cause of a false, air-bone gap? - ANS collapsed ear canal normal size of cochlea in adults - ANS 1 cm width, 5 mm height ABLB test is used for: - ANS used clinically to determine whether loudness recruitment is present in the abnormal ear in a patient with unilateral hearing loss. behavioral test tone decay test - ANS is used in audiology to detect and measure auditory fatigue. behavioral test if IA is increased, how does the masking plateau change? - ANS plateau becomes wider ABR test purpose and definition - ANS adults. The Auditory Brainstem Response or ABR is a neurological test; it's similar to an EEG. To complete the test, the doctor will play sounds (click bursts) into the ears through headphones and then measure responses from the ear, hearing-nerve and brain with electrodes placed on the forehead and behind the ears. some causes of auditory nerve disorders - ANS meningitis, high blood pressure, tumor what does audiometric zero mean? - ANS all frequencies can be heard (per practice test answer..) formants - ANS certain harmonics are relatively loud in the sound spectrum conditioned orientation reflex (COR) - ANS verifies localization of sound for children w/ visual reinforcement by head movement