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Operating Temperature Range:
59° to 95°F (15° to 35°C).
All specifications apply over this temperature range.
Frequencies:
500, 1000, 2000 and 4000 Hz ±3%.
Distortion:
Less than 3% total harmonic distortion (as measured at
transducer input).
Rise/Fall Times:
60 ±40 msec. as measured between the -1 and
-20 dB points.
Tone Duration:
1.5 ±0.2 sec.
Pause Between Tones: Varied:
between 1.0 and 2.0 seconds.
Sound Level:
Sound levels were established by threshold loudness
balance method to TDH-39 receiver with MX41/AR cushion per
ANSI S3.6 -1969 Ref. Thresholds.
These levels were established in an independent study and are
equivalent to standard audiometric headphones.
5
±3 dB @ 500, 1000 and 2000 Hz ±4 dB @ 4000 Hz. This corre-
sponds to the following absolute sound pressure levels when the
instrument is coupled to an occluded ear simulator per ANSI Std.
No. S3.25-1979.
Actual Sound Level (dB re 20 uPa)
Freq. (Hz)
For 20 dB HL
For 25 dB HL For 40 dB HL
500
29.9
34.9
49.9
1000
27.3
32.3
47.3
2000
32.7
37.7
52.7
4000
33.9
38.9
53.9
5. Bienvenue, G., Michael, P., Chaffinch, J. — “Reference Threshold Sound Pressure Levels for
the Welch Allyn Audioscope”,
Acoustical Society of America,
1984
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