1717
NOISE CRITERION CURVES5
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
OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 μbar)
BAND CENTER FREQUENCIES, Hz
PCA-M50KA
NOTCH
High
Medium1
Medium2
Low
SPL(dB)
40
37
34
32
LINE
NOTCH
High
Medium1
Medium2
Low
SPL(dB)
40
37
35
33
LINE
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
OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 μbar)
BAND CENTER FREQUENCIES, Hz
PCA-M60KA
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
BAND CENTER FREQUENCIES, Hz
OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 µbar)
PCA-M71KA
NOTCH
High
Medium1
Medium2
Low
SPL(dB)
41
39
37
35
LINE
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
OCTAVE BAND SOUND PRESSURE LEVEL, dB (0 dB = 0.0002 μbar)
BAND CENTER FREQUENCIES, Hz
PCA-M35KA
NOTCH
High
Medium1
Medium2
Low
SPL(dB)
39
36
33
31
LINE