5
NOISE CRITERION CURVES
5-1. SOUND LEVELS
Measurement location
* Measured in anechoic room.
5-2. NOISE CRITERION CURVES
70.0
65.0
60.0
55.0
50.0
45.0
40.0
35.0
30.0
25.0
Approximate minimum
audible limit on
20.0
continuous noise
15.0
10.0
63
125
250
OCH660
1.0m
High
Low
500
1k
Octave band center frequencies (Hz)
Model
PKA-M35/50HA(L)
NC-60
NC-50
NC-40
NC-30
NC-20
2k
4k
8k
13
Sound level at anechoic room : Low-Middle-High
Sound level dB (A)
36 - 40 - 43