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54 Cards in this Set
- Front
- Back
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Several techniques to obtain pure-tone thresholds are accepted by the audiological community. Name two.
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Carhart & Jerger (1959) modification of the Hughson & Westlake (1944) approach.
ANSI (2004) and ASHA (2005) sound testing methods. |
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Why are there guideline that present a recommended set of procedures based on existing practice and research findings?
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To suggest standard procedures that in the final analysis should benefit the patient.
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What is the purpose of testing guidelines?
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To improve inter-clinician and inter-clinic comparisons of data, allowing for a more effective transfer of information.
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What is the test method recommended by Carhart & Jerger and ASHA for air conduction testing?
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The ascending technique.
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What is the ascending technique?
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The recommended air conduction testing method for arriving at a patient's hearing threshold. We come from below the client's threshold and intensity and raise them until we find the client's threshold.
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What is the basic procedure for determining threshold?
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1. familiarization with test signal
2. threshold measurement The procedure is the same regardless of frequency, output transducer, or ear under test. |
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What does familiarization refer to?
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Threshold testing begins by familiarizing the patient with a 1000 Hz test tone and making a ballpark guesstimate or gross search of approximately where the threshold might be.
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What is the purpose of familiarization?
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To assure the clinician that the patient understands and can perform the response task. It is a recommended practice for general populations and should be used whenever warranted by the mental or physical status of the patient.
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What are the methods of familiarization that are commonly used?
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1. A 1000-Hz tone is presented at a 30 dB hearing level. If a clear response occurs, begin threshold measurement.
2. If no response occurs, present the tone at 50 dB HL. 3. Add successive additional increments of 10 dB until a response is obtained. (If clinical history indicates a profound hearing loss, the audiologist may begin the familiarization process at a higher presentation level. Commonly, audiologists begin at 40 dB.) |
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What do you do after the gross threshold search is complete?
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Begin fine threshold search.
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What technique is used to begin the fine threshold search?
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The ascending technique - beginning with an inaudible signal - is recommended as a standard procedure for manual pure-tone threshold audiometry.
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What standard issues should be observed when testing?
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1. Tone - pure-tone stimuli of 1 to 2 seconds.
2. Interval between tones - varied but not shorter than the test tone. 3. Level of first presentation - should be below the expected threshold. 4. Levels of succeeding presentations - determined by the preceding response. After each failure to respond to a signal, the level is increased in 5-dB steps until the first response occurs. After the response, the intensity is decrease 10 dB, and another ascending series is begun. |
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What is the method for conducting the threshold search?
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1. The tone is presented 10 dB below where the patinet responded during familiarization.
2. The level of the tone is raised in 5 dB steps until the patient responds. 3. The tone is then decreased by 10 dB and presented again. 4. The level of the tone is then raised 5 dB until the patient responds. 5. Steps 2 and 3 are repeated until the patient responds at the same frequency 2 out of 3 times. |
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What is a threshold?
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When you get 2 responses out of 3 presentations at the same level.
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Name the 2 parts of the pure-tone testing procedure.
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1. Raise or lower the intensity of the tone in fairly large steps to quickly find the ballpark location of the threshold.
2. Switch to a more formal threshold determination strategy in which the threshold is approached from below in 5 dB steps. |
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What is meant by the "up-5, down-10" technique used in pure tone air conduction testing?
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Whenever the patient does not hear the tone, we increase the level of the next tone by 5 dB. Whenever the patient hears the tone we decrease the level of the next tone by 10 dB.
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Why is up-5, down-10 confusing when looking at an audiogram?
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Because the lower intensity levels are listed at the top (down-10) and the higher intensity levels are listed at the bottom (up-5). It looks backwards.
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How many threshold tests must be conducted?
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A separate threshold is needed for every test frequency for both ears and for both air and bone conduction. Pure tone thresholds are routinely tested separately for each ear, followed by bone conduction. The threshold search procedure is performed many times for each patient.
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What frequencies are tested during clinical pure tone testing?
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250 Hz - 8000 Hz. ASHA (2005) standards state that threshold assessment should be made at 250, 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz, except when a low-frequency hearing loss exists, in which case the hearing threshold at 125 Hz should also be measured.
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When should inter-octave measurements be made?
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When a difference of 20 dB or more exists between the threshold values at any two adjacent octave frequencies from 500 to 2000 Hz, inter-octave measurements at 750 Hz and 1500 Hz should be made.
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What is the proper order to the frequency testing?
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1. Test the better ear first; if unknown, test the right ear.
2. The initial test frequency should be 1000 Hz. 3. Follow in order - 2000, 3000, 4000, 6000, 8000 Hz 4. Retest at 1000 Hz 5. Test 500, 250 and 125 Hz (if needed). |
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Why do we need to retest 1000 Hz?
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It is the most frequently heard frequency. It has the best test, retest reliability.
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What is good test/retest reliability?
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If the threshold at 1000 Hz is within 5 dB the second time of the first time we found.
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Why is a 10 dB difference a problem when retesting 1000 Hz?
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It's difficult to understand why the patient would not give you the threshold or somewhere close to the same threshold the second time. That would have to be investigated closely and may require retesting of the other frequencies as well.
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Which is completed first - air conduction or bone conduction?
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Air conduction
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Where is the bone oscillator placed?
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On the mastoid process.
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What does a bone conduction test determine?
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The threshold of the cochlea directly, and establishes if a conductive component exists at any frequency in the hearing loss of the patient.
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What are the difference between air conduction threshold testing and bone conduction threshold testing?
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In bone conduction, you would go below the threshold established by air conduction to begin the testing.
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What frequencies are used and in what order are they tested in bone conduction testing?
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1. 1000, 2000, 4000
2. retest 1000 3. 500 and 250 Many audiologists do not perform the 1000 Hz reliability check or test semi-octaves by bone conduction unless there is reason to do so. However, a 3000 Hz bone conduction threshold is recommended if that frequency was tested by air conduction. |
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When you put the receiver on the right mastoid process and complete an unmasked bone conduction test for that ear, you may not have a bone conduction threshold for the right ear. Why?
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This is due to inter-aural attenuation, which is the loss of energy of a sound presented by either air conduction or bone conduction as it travels from the test ear to the non-test ear. It is the number of decibels lost in cross hearing.
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In bone conduction testing,...
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whichever cochlea is better at that frequency will respond.
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What are the 3 contributors to the total bone conduction perception process?
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1. distortional bone conduction (main player)
2. Inertial bone conduction 3. Osseotympanic bone conduction |
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How does the occlusion effect come into play in audiometric testing?
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When we place an earphone, particularly a supra aural earphone, over the ear, we're occluding the external auditory canal with the earphone. A stronger signal reaches the cochlea when bone conduction signals are presented with the ears occluded compared with the unoccluded.
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Occlusion effect
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If we present bone conduction stimuli to an ear occluded by an earphone, there will be an increase of sound delivered by a bone conduction vibrator to the cochlea.
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T/F - you should leave earphones on when performing bone conduction testing.
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False (unless delivering masking to the non test ear)
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What do we need to be aware of when using ear phones during bone conduction testing?
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The non test ear might be enhanced with the occlusion effect. A given bone conduction signal will sound louder with the ears covered compared with the ears open.
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What are two contributions of Distortional Bone Conduction?
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1. Role of the inner ear.
2. Primary contributor to BC thresholds. |
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What are two contributions of Inertial Bone Conduction?
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1. Role of the middle ear.
2. Lag of the middle ear bones. |
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What are three contributions of Osseotympanic Bone Conduction?
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1. Role of the outer ear
2. Osseus = bone 3. Tympanic = tympanic membrane |
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What happens after you have found the thresholds and recorded them on the audiogram?
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You can begin to interpret the results to determine the type and severity of hearing loss.
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Results of hearing tests are looked at for each frequency in terms of:
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1. the amount of hearing loss by air conduction
2. the amount of hearing loss by bone conduction 3. the relationship between AC and BC |
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T/F: The entire ear is tested by air conduction.
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True. The signal from an earphone must be processed through the outer, middle, and inner ear and the auditory nerve.
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What do AC thresholds show?
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The total amount of hearing loss that is present.
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Which tests only the sensorineural mechanism?
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Bone conduction
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Air-bone gap
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The difference between the AC thresholds and the BC thresholds at the same frequency - implies a conductive hearing loss.
The pathway of the whole ear minus the sensorineural hearing loss will equal the conductive part of the hearing loss. |
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What can we determine from the type of hearing loss a patient has?
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What part of the auditory pathway is causing the hearing loss.
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What are four conclusions that can be drawn from the results of hearing testing?
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1. normal hearing
2. conductive hearing loss 3. sensorineural hearing loss 4. mixed hearing loss |
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What is a conductive hearing loss?
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When sound can't reach the inner ear.
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How is frequency sensitivity affected with a conductive hearing loss?
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The patient typically demonstrates decreased sensitivity across all frequencies.
Sometimes hearing is better for the higher frequencies than it is for the lower ones. |
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How would you know a patient has a sensorineural hearing loss from reading an audiogram?
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The BC results are the same as the AC results. They are almost superimposed on each other.
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What is a common type of hearing loss seen in older adults?
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A bilateral sloping mild to profound SNHL.
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How are frequencies divided into low, middle and high?
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Low: 250 Hz to 750 Hz
Middle: 1000 Hz to 3000 Hz High: 4000 Hz to 8000 Hz |
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What is a profound hearing loss?
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The hearing loss is 90 dB or greater.
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What is the pure tone audiometric pattern for a mixed hearing loss?
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It will include bone conduction thresholds below 20 dB HL at some or all frequencies. A sensorineural component is also present. So, the sensorineural component is the loss by bone conduction, and the conductive component is the air-bone gap.
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