Term
| Device for measurement of frequency-weighted sound pressure level |
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Definition
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Term
Sound Level Meter:
-What are the components of a sound level meter?
-Used to measure SPL in a ___ or in ___ ___ |
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Definition
| Components: microphone, pre-amp, detectors to give signal level, standardized weighting settings, and a display; coupler; sound field; |
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Term
ANSI S1.4-1983 (R2006) classifies SLMs on the basis of features:
-Type __ – high precision, laboratory use
-Type __ – very precise
-Type __– general purpose
-___ ___ – hobby |
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Definition
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Term
| For audiometer calibration, at minimum a Type __ with ____ octave band filter and ___ microphone should be used |
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Definition
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Term
Microphone:
-Converts fluctuations in air pressure at the diaphragm to an ___ signal
-Typically ___ type microphone, ¼ or ½ inch |
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Definition
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Term
SLM features-Electret condenser microphone:
-___ noise level, ___ frequency response over a broad range of frequencies, ___ growth of loudness
-Pressure condenser microphone should be used for ___
measurements
-Sound field condenser microphone should be used for ___ measurements |
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Definition
| Low; flat; linear; coupler; loudspeaker |
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Term
SLM features-Electret condenser microphone:
-SLMs usually employ a ___ -inch omnidirectional microphone
-Good ___ response (larger microphones are less sensitive to frequencies above ~ 5kHz)
-Good response to ___ within the intensity range commonly
encountered in sound level measurements (up to about 140
dB SPL)
-ANSI ____ – 1967 (R2003)-Specifies microphones suitable for sound measurement and calibration |
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Definition
| ½; frequency; sound; S1.12 |
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Term
SLM microphone directionality:
[image] |
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Definition
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Term
| increases the intensity of the signal to a level that is readable by the instrument |
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Definition
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Term
Frequency Weighting Networks:
-___ the signal to correspond to an appropriate response algorithm (i.e., dbA)
-Standard weighting: Excludes energy outside of the ___-___ Hz range and increases signal strength between ~ ____ and ___ Hz |
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Definition
| Modify; 20 – 20k; 500 and 3000 |
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Term
| ____ voltmeter: provides a numerical readout of the signal strength. Logarithmic scale (dB) |
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Definition
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Term
Response Integration Time (Time Weighting):
-Refers to rate at which signals are ___
-Slow (samples every 1 sec): appropriate for signals with level
fluctuations greater than __ dB (masking signals, ambient noise)
-Fast (samples every 125 msec): appropriate for signals with ___ or ___ level fluctuations (pure tones)
-Impulse (asymmetrical - samples every 35 msec when SPL increases, every 1.5 when SPL decreases) : response to maximum intensity of ___ impulse sounds
-Peak (no time constant): response to ___ intensity of impulse sound, even if it is just a ___ sound |
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Definition
| sampled; 4; few or no; repeated; maximum; single |
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Term
Time weighting: Which one is which?
[image] |
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Definition
| The top one is fast and the bottom one is slow |
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Term
Integrating SLM:
-Measures and calculates total ___ ___ over a period of
time
-Useful to calculate measures such as Leq |
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Definition
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Term
Integrating SLM:
[image]
Which one is which from top to bottom?
On the bottom picture, what does the red line represent? |
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Definition
| Standard SLM output; Accumulated sound energy over measurement period; Line represents cutoff for harmful exposure-all energy above line is dose over measurement period |
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Term
Octave Band Filtering:
-Allows measurement within a ___ frequency range
-Appropriate for measuring ___ ___ or other ____ signals without interference of ambient noise or other sound outside of the band range |
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Definition
| narrow; pure tones; narrow-band |
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Term
SLM microphone calibration:
-___, sound level ___, or ___ calibrator placed over the microphone
-Generates a known SPL at one or more frequencies. Typically ___ dB SPL at ___ Hz
-SLM reading adjusted to match the ___ |
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Definition
| Pistonphone; calibrator; acoustic; 114; 1000; output |
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