OC275-12
90
80
70
60
50
40
30
20
10
63
125
250
500
1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
PK30FL3
PK36FL3
Hi
NOTCH
Lo
49
SPL(dB)
44
LINE
7. NOISE CRITERION CURVES
90
80
70
60
50
40
30
20
10
63
125
250
500
1000 2000 4000 8000
APPROXIMATE
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
OCT
A
VE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
PK18FL3
PK24FL3
Hi
NOTCH
Lo
48
SPL(dB)
41
LINE
Wall
Unit
3.3ft
3.3ft
Ambient temperature 80˚F
Test conditions are based on JIS Z8731
OC275--1.qxp 01/12/14 3:06 PM Page 12
