Term
Purpose of Calibration of the Audiometer:
-Verify that test equipment and signals are still
performing within ___ tolerances
-Verify ___ among test signals that produce comparable test results
-Correct for ___ that have occurred since the last check |
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Definition
| manufacturer / standard; consistency; changes |
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Term
| ____ ____-____ presents all aspects of the standards for audiometers including distortion, allowable frequencies, values for zero HL for various transducers, etc.Developed in 1969, revised in 1989, 1996, 2004, and 2010 |
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Definition
| ANSI S3.6 – 2010: American National Standard Specification for Audiometers |
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Term
ANSI S3.6-2010:
-Consistent with ___ and ___ standard procedures. Ensures that all audiometers meet the same specifications ___ in the world they are manufactured and/or used
-Describes processes for ___ ear (rather than real
ear) evaluation of audiometer function |
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Definition
| IEC; ISO; anywhere; mechanical |
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Term
| Measures the electrical potential difference between two points in an electric circuit |
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Definition
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Term
| What are the 3 different domains of calibration checks? |
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Definition
| intensity, frequency, and time |
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Term
The voltmeter/multimeter...
-Can measure ___ output from an electrical device
-Can be used to determine the location of electrical ___ |
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Definition
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Term
| Device for measurement of sound pressure level. Used to measure SPL in a coupler or in sound field |
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Definition
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Term
ANSI S1.4-1983 (R2006) classifies SLMs on the basis of features:
-Type 0 – ___ ___, laboratory use
-Type I – ___ ___
-Type II – ___ ___
-Other types –___ |
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Definition
| high precision; very precise; general purpose; hobby |
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Term
| For audiometer calibration, at minimum a Type __ with one-third octave band filter and ___ microphone should be used |
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Definition
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Term
| Chambers used to simulate the acoustical and physical properties of a human ear |
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Definition
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Term
Acoustic Couplers:
-Used to connect headphone/earphone to ___
instrument (typically, a sound level meter)
-Standardized ___ and ___-Enclose __ cubic cm of air in the ear canal when you put a supra-aural headphone on
-May contain a calibrated ___ |
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Definition
| measurement; shape; volume; 6; microphone |
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Term
| simulates human ear up to 10,000 Hz. 3 cavities with 3 different volumes. Could be used for circumaural headphones |
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Definition
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Term
| encloses 2 CC of air approximating what would be between an insert and the TM. Used for inserts |
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Definition
Hearing aid couplers (HA-1 and HA-2)
[image] |
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Term
Coupler Applications-Artificial Ear:
-Enables measurement of ___ from air-conduction transducers (headphones and insert earphones)
-Exerts appropriate ___ to hold the headphone in place
-Interchangeable couplers allow measurement from ___ transducers
-Rubber feet minimize ___ |
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Definition
output; force; multiple; vibration
[image] |
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Term
-The goal of the output check is to make sure the attenuator dial setting matches actual ___ level of test signals as closely as possible
-Output intensity checks are conducted for ___ transducers
-Output levels are expected to ___ from transducer to transducer; therefore, there is no ___ meaningful output level from the audiometer to measure
-Transducer-___ check |
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Definition
| intensity; all; vary; single; dependent |
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Term
| What does RETSPL stand for? |
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Definition
| Reference Equivalent (Threshold) Sound Pressure Level |
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Term
-___ is the sound pressure level measured at a reference point which corresponds to (is equivalent to) threshold.
-Ex: If threshold (zero SL) is 16.5 dB SPL for Transducer X at Y Hz, then the RETSPL for that transducer, at that frequency, in that test condition, is ___ |
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Definition
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Term
-Equipment: ___ microphone, ___
-Place earphone on ___ with a weight on top of it (for supra-aural headphones)
-For inserts, receiver tube is connected to adapter ___ of HA-2 coupler (no weight needed)
-Output is read as __, converted to dB SPL (re: 20 μPa), then compared to expected values at each frequency
-Reference SPL values provided in ISO 389-1 and ANSI S3.6 |
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Definition
| condenser; couplers; coupler; nipple; V |
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Term
When output has been established:
1. Attempt to bring audiometer into calibration using ___ ___
2. Use ___ sheet if necessary
3. If audiometer is off by more than __ dB at any frequency or by __ dB at three or more frequencies, contact service technician for recalibration and transducer check |
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Definition
| trim potentiometers ; correction; 15; 10 |
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Term
| -Goal of Linearity Check: ___ signals should be attenuated by the dial in as linear a fashion as possible (i.e., turning the dial X degrees always changes the attenuation by Y dB) |
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Definition
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Term
Linearity Check:
-Transducer-independent check – linearity may be evaluated ___ (directly from the audiometer) or ___
(through a transducer)
-___ measurement: supra-aural earphone placed on an 6-cc coupler connected to a SLM with a one-third octave band filter
-___ measurement: voltmeter connected between audiometer output and earphone using a patch cord; electronic load in line to simulate earphone impedance |
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Definition
| electronically; acoustically; Acoustical; Electrical |
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Term
Linearity Check
-Turn audiometer to maximum output, then attenuate in 5-dB steps until output can no longer be ___
-Acoustical technique: unit measure is dB ___
-Electrical technique: unit measure is ___ |
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Definition
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Term
Linearity Check:
-Tolerance: decreases should be linear within __% of the interval step or __ dB, whichever is smaller
-Example: for a 5 dB step size setting, each attenuation should be between __ and __ dB |
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Definition
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Term
Frequency Calibration Equipment:
The ___ allows visual inspection of
signal voltages, usually as a graph of one or more electrical potential differences as a function of time |
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Definition
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Term
The oscilloscope allows user to....
-Determine the ___ of an input signal
-Determine the ___ ___ of an input signal
-Detect ___ in a signal
-Determine whether a signal is ___ or ___
-Measure ___/___ time of a transient signal
-Test for ___ in multichannel instruments |
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Definition
| voltage; time value (duration); distortion; AC; DC; rise/fall; crossover |
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Term
Frequency Calibration Equipment:
-The ___ ___ is a device that stores and displays the number of times (cycles) a particular input has been received
-The ___ ___ is a transform
function (Fourier transform) to analyze the frequency composition of an input signal |
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Definition
| frequency counter; spectrum analyzer |
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Term
Frequency Calibration Equipment:
-The ___ ___ is a device that measures an input voltage signal
and calculates the energy at a target frequency
-Remaining total energy in the input is considered ___ energy |
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Definition
| distortion meter; distortion |
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Term
| Goal of frequency check: Frequency readout should ___ actual frequency of test signals as closely as possible |
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Definition
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Term
Frequency Check:
-Equipment: electronic ___ or ___ ___
-Electronic counter gives a precise reading of ___ frequency
-Oscilloscope can be used for this purpose but with less ___. Typically accurate only within ___%; 1-3% is desirable |
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Definition
| counter; frequency analyzer; output; precision; 5 |
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Term
Frequency Check:
-Connect electronic counter between audiometer ___ and ___ using patch cords
-Transducer-___ check
-Set attenuator dial so that output is sufficient to ___
the counter
-Measure frequency for each setting on the frequency ___ |
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Definition
| output; earphone; independent; activate; control |
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Term
Frequency Check-Standard tolerances for audiometer types:
-Type 1: +/- __% of nominal
-Type 2: +/- __%
-Type 3-5: +/- __% |
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Definition
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Term
| Goal of distortion check: Output signals should contain as little ___ energy (energy at frequencies other than the frequency of the test signal) as possible |
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Definition
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Term
Distortion Check:
-Harmonic distortion should be checked through ___
-Equipment: SLM w/ ___ band filter, ___
-Distortion will appear as attenuation which is not ___, particularly at high output levels (___ dB and above) |
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Definition
| transducers; octave; couplers linear; 90 |
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Term
Distortion Check:
-Place earphone on appropriate ___ with microphone connected to a SLM with ___ octave band filter
-Adjust ___ dial to appropriate setting for frequency tested. Goal is to be out of the noise floor.
-With octave band filter adjusted to match frequency being tested, measure output ___. Change filter to ___ harmonic, measure, output. Repeat until all ___ frequency harmonics are measured.
-Tolerance: total harmonic distortion less than or equal to ___% |
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Definition
| coupler; 1/3; attenuator; SPL; second; higher; 2.5 |
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Term
FM Signal Check:
-FM capability is a requirement of Type __ and __ audiometers
-FM defined by three characteristics: ___, ___ ___, and ___ ___
-Transducer-___ check |
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Definition
| 1 and 2; carrier, modulation rate, and frequency deviation; independent |
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Term
-___ is the center or nominal frequency– the setting of the frequency dial
-Tolerance: +/- ___% |
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Definition
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Term
___ ___ is the number of times the FM signal completes a modulation cycle per second
-Tolerance: +/- ___% |
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Definition
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Term
The ___ ___ frequency range over which change occurs for each modulation
-Tolerance: +/- ___% |
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Definition
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Term
Time Calibration:
-___ ___ ___ is a device for recording signal level (in dB) over time
-Provides a visual representation of the ___ ___ in an electrical (or acoustic) signal |
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Definition
| graphic level recorder; time variation |
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Term
| ___-___ ___ check is a check to determine the precision of the audiometer in rising to desired output levels and descending back to zero |
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Definition
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Term
Rise-Fall Time Check:
-Goal I: Output signals should increase from zero to desired output level (rise time) at a ___ rate every time they are presented, and should decrease from test level to zero (___ ___) at a consistent rate
-Goal II: Rise and fall time should be ___, ___, and ideally ___ one another |
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Definition
| consistent; fall time; short; reliable; match |
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Term
Rise-Fall Time Check:
-Equipment: ___
-____ routed directly from audiometer into oscilloscope
-Transducer-___ check
-Typically tested using a ___ Hz tone, but it is good practice to check all frequencies from 250 to 6000 Hz |
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Definition
| oscilloscope; Output; independent; 1000 |
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Term
Rise-Fall Time Check:
-The ___ ___ is ength of time in msec (after interrupter switch is activated) between when signal is at target intensity -20 dB and when signal is at target intensity -1 dB. Time it takes for signal to go from x-20 to x-1. |
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Definition
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Term
| Inverse of rise time-time from x-1 to x-20 |
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Definition
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Term
| ANSI S3.6 – 2004 specifies rise/fall times should be between __ and ___ msec |
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Definition
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Term
Pulsed Signal Check:
-Type 1 and 2 audiometers are required to have capability to produce ___ tones |
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Definition
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Term
Pulsed Signal Check:
-Rise and fall times should be between ___-___ msec
-Plateau of the pulse tone no less than ___ msec
-Intensity difference between “on” and “off” phases of each pulse must be at least ___ dB
-Transducer-___ check |
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Definition
| 20-50; 150; 20; independent |
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Term
| What coupler is used for the calibration of bone oscillators? |
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Definition
| Mechanical Coupler a.k.a. “artificial mastoid” |
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Term
| When was the Mechanical Coupler invented? |
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Definition
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Term
Artificial Mastoid:
-Standardized mechanical impedance - inertial ___ simulates the mechanics of the human head
-Contains built-in ___ force transducer
-___ ___ holds the bone oscillator in place at a standard force which can be adjusted (typically) between 2 and 8 N
-Transduces the force from a bone-conduction oscillator to an ___ signal |
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Definition
| mass; electromechanical; moveable arm; electric |
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Term
| What is a popular type of artificial mastoid? |
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Definition
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Term
Bone oscillator calibration:
-Oscillator mechanism removed from the headband and placed on the ___ ___, using the weighted arm to create the appropriate pressure
-___ Newtons, +/- .5 for mastoid placement
-Forehead placement requires ___ force on the oscillator to obtain comparable thresholds
-A ___ ___ ___ is used to measure the output of the bone
oscillator and compared to normative values based on bone oscillator RETSPLs |
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Definition
| artificial mastoid; 5.4; more; sound level meter |
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Term
Intensity and Frequency Checks:
-Similar method to calibration of ___-___ transducers
-Artificial mastoid output to the SLM with ___-___ filter
-all checks of bone oscillator are transducer-___ |
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Definition
| air-conduction; octave-band; dependent |
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Term
-Distortion in the bone oscillator may be measured by connecting the output of the artificial mastoid to a ___ ___
-Only need to check frequencies that are used for ___ ___ using the bone oscillator
-Tolerance: THD less than or equal to ___% |
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Definition
frequency analyzer; audiometric
testing; 5.5 |
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Term
Real-ear calibration of bone conductors is not recommended because methods require assumption that AC and BC
thresholds are ___ for normative group and it does not account for ___ noise in test room |
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Definition
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Term
Masking:
-May be generated by an ___ device (masking generator) or, more often, by the ___
-Masking outputs through all transducers should be ___ after verifying that the transducers themselves are working properly
-It is necessary to ___ all masking noises used for audiometric testing. White noise, weighted random noise for masking of speech, and narrow band noise are all defined by ANSI ___-___
-In general, the same checks are used for masking noises as are used for other ___ signal outputs. Linearity check, output check, etc |
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Definition
| external; audiometer; checked; calibrate; S3.6-2004; audiometer |
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Term
Narrow Band Noise Calibration:
-Bandwidths are measured using a ___ analyzer
-Calibrated to the ___ ___ for each frequency
-Critical bandwidth: NBN will just mask a tone with the same ___ as the NBN center frequency at an SNR of -4 dB |
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Definition
| spectrum; critical bandwidth; frequency |
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Term
Narrow Band Noise Calibration:
-___ level (measured using an SLM with octave band filter) calibrated in dB EML
-___ ___ ___: SPL of a masking signal that masks a pure tone at 0 dB HL 50% of the time when the masking signal and pure tone are presented to the same ear
-ANSI S3.6 specifies that NBN masking must range from __ dB EML to maximum ___-___ HL for each frequency, but should not exceed 115 dB SPL at any frequency |
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Definition
| Output; EML (Effective Masking Level); 0; air-conduction |
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Term
Narrow Band Noise Calibration:
-Linearity of NBN masking should be measured the same way ___-___ linearity is measured |
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Definition
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Term
White Noise:
-Typically calibrated in dB ___, but can be calibrated in ___
-Frequency response of masker: white noise SPL should be within +/- __ dB of the level at 1000 Hz from 250 to 5000 Hz
-In other words, if the white noise is 45 dB SPL when measured
at 1000 Hz, it should be between ___ and ___ dB SPL at all other
frequencies between 250 and 5000 Hz
-Can be ascertained using an ___ ___ ___ + ___ ___ ___ or with a spectrum analyzer |
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Definition
| SPL; EML; 5; 40 and 50; SLM; octave band filter |
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Term
White Noise:
-Output response of masker: measured white noise output should be within ___ to ___ of nominal output (number on the masking level dial) |
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Definition
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Term
-Transducer output levels should be checked every ___ months or more often if you have reason to believe the output has changed
-Old equipment should be checked at least ___ per year |
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Definition
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Term
Examples of red flags in audiometers:
-The same air-bone gap is seen in two ___ patients
-BC thresholds are significantly ___ than AC thresholds
-Audiometric thresholds do not seem to ___ with other test results or your subjective impressions
-Patient reports hearing ___ sounds (particularly a patient who has been tested in the clinic before) |
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Definition
| successive; worse; agree; unusual |
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