14
15
OCH660A
5
NOISE CRITERION CURVES
* Measured in anechoic room.
PKA-M35/50HA(L)
36 - 40 - 43
Sound level dB (A)
Sound level at anechoic room : Low-Middle-High
1.0m
1.0m
Measurement location
Model
Wall
Main unit
5-1. SOUND LEVELS
5-2. NOISE CRITERION CURVES
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
63
125
250
500
1k
2k
4k
8k
NC-60
NC-50
O
ct
a
ve
b
a
n
d
p
re
ssu
re
l
e
ve
l
(d
B
)
0
d
B
=
2
0
μ
P
a
Approximate minimum
audible limit on
continuous noise
NC-40
Octave band center frequencies (Hz)
NC-20
NC-30
High
Low
