Term
sound pressure level at the microphone opening of the HA |
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Definition
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Term
the difference between the output SPL in a coupler and the input SPL (output SPL-input SPL = this) |
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Definition
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Term
a manual or electronic adjustment for overall gain |
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Definition
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Term
What are key components of probe-mic equipment? |
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Definition
Tone/noise generator, amplifier, loudspeakers (generate stimuli), reference mic (monitors the SPL reaching the aid from the loudspeaker & adjusts the sound’s volume if the level is too high or too low). |
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Term
Where is the reference microphone placed? |
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Definition
placed next to HA microphone |
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Term
Describe the importance of calibration |
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Definition
To check that the correct input levels are generated |
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Term
Describe the importance of electroacoustic analysis: -What: obtaining various measures of ___ ___ ___ in a test box -Why: For ___ control; provides a standard way to check hearing aid ___; can compare results to how aid ___ worked -How: We connect hearing aid to a ___, place it in a small ___, then run a test in the test box. |
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Definition
hearing aid function; quality; function; originally; coupler; chamber |
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Term
Appropriate settings for electroacoustic analysis: -___ coupler: small cavity that connects a hearing aid to a measurement microphone -BTE = use ___ coupler -ITEs & ITCs = use ___ coupler (attach with putty) -RIC = use ___. May need to use an “adapter” |
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Definition
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Term
How to set up HA appropriately for EC: -Plug ___ on faceplate side of aid -Set aid to ___-directional mode, ___ frequency response, greatest HFA-OSPL90, greatest HFA-FOG. -Disable ___ features (i.e. noise reduction, feedback suppression). -All tests performed with AGC set for ___ effect. Except for attack and release time tests and input-output tests. -There is no standard coupler for ___-fit HAs. Most are specified as BTEs using an earhook. |
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Definition
vent; omni; widest; adaptive; minimum; open |
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Term
has several cavities to simulate a real adult’s ear (i.e. to mimic change of impedance as freq changes) |
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Definition
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Term
What is an example of an ear simulator? |
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Definition
Zwislocki coupler. Main cavity(0.6cc) is connected to 4 other cavities (0.1 to 0.22 cc) by small tubes & dampers |
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Term
ANSI specifies measuring HAs in __ ___ and IEC standards specifies measuring HAs in ___ ___ |
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Definition
2-cc coupler; ear simulator (but allows coupler) |
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Term
Name two companies that make test boxes for electrocoustic analyses |
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Definition
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Term
Telecoil: -An inductive pick-up coil used to sense changing ___ fields -Converts magnetic energy into ___ energy -Mic converts acoustic energy to ___ energy |
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Definition
magnetic; electrical; electrical |
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Term
generation of an electric current or magnetic state by proximity to a different source of electricity or magnetism |
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Definition
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Term
conductor wound into a spiral to create a high concentration of material into which current flow is induced when a magnetic field enters its vicinity |
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Definition
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Term
In a hearing aid, the ___ is the induction coil and the ___ produces the magnetic field |
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Definition
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Term
continuous wire surrounding a room that conducts electrical energy from an amplifier |
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Definition
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Term
coupler SPL for an inductive telephone simulator |
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Definition
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Term
coupler SPL in a vertical magnetic field |
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Definition
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Term
The average of values at 1000, 1600, and 2500 Hz |
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Definition
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Term
Coupler SPL as a function of frequency for 90 dB input SPL |
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Definition
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Term
The maximum value of the OSPL90 curve |
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Definition
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Term
Average of the OSPL90 values |
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Definition
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Term
Average of the full on gain at the HFA frequencies |
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Definition
HFA full-on gain (HFA-FOG); input is 50 dB SPL |
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Term
What are the tolerances for maximum OSPL90, HFA-OSPL90, HFA full on gain (HFA-FOG), |
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Definition
OSPL90=plus or minus 3 HFA-OSPL90=plus or minus 4 HFA full on gain (HFA-FOG)=plus or minus 5 |
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Term
gain control (VC or overall gain control) setting to produce an HFA-gain within +/- 1.5 dB of the HFA-OSPL90 minus 77 dB for a 60 dB SPL input |
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Definition
Reference test setting (RTS) |
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Term
If HFA FOG for a 60 dB SPL input is less than HFA-OSPL90-77 dB, then RTS is ___-___ ___ of gain control |
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Definition
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Term
average of the gain at HFA freqs for a 60 dB SPL input, with gain control set at RTS |
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Definition
Reference test gain (RTG) |
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Term
range between the lowest & highest freqs. at which the freq. response curve is 20 dB below its HFA value |
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Definition
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Term
distortion components relative to the total power of the signal (expressed in dB or a percentage) |
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Definition
Total Harmonic Distortion (THD) |
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Term
THD is measured by putting a ___ dB SPL pure tone into HA (set to RTS) & analyzing the output waveform |
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Definition
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Term
quantifies the internal noise of HA |
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Definition
Equivalent Input Noise (EIN) |
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