6. NOISE CRITERION CURVES
PKH18FL
PKH24FL
90
80
70
60
50
40
30
APPROXIMATE
20
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
10
63
PKH30FL
PKH36FL
90
80
70
60
50
40
30
APPROXIMATE
20
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
10
63
NOTCH
Hi
Lo
125
250
500 1000 2000 4000 8000
BAND CENTER FREQUENCIES, Hz
NOTCH
Hi
Lo
125
250
500 1000 2000 4000 8000
BAND CENTER FREQUENCIES, Hz
Ambient temperature 80˚F
Test conditions are based on JIS Z8731
SPL(dB)
LINE
48
41
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
SPL(dB)
LINE
49
44
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
15
Unit
Wall
3.3ft
3.3ft