5
NOISE CRITERION CURVES
PLA-A12EA7
90
80
70
60
50
40
30
APPROXIMATE
20
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
10
63
125
250
BAND CENTER FREQUENCIES, Hz
PLA-A24EA7
90
80
70
60
50
40
30
APPROXIMATE
20
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
10
63
125
250
BAND CENTER FREQUENCIES, Hz
OCH640C
NOTCH SPL(dB)
LINE
High
30
Medium1
29
Medium2
28
Low
27
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
500
1000
2000
4000
8000
NOTCH SPL(dB)
LINE
High
36
Medium1
33
Medium2
30
Low
28
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
500
1000
2000
4000
8000
13
13
PLA-A18EA7
90
80
70
60
50
40
30
APPROXIMATE
20
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
10
63
125
250
BAND CENTER FREQUENCIES, Hz
PLA-A30EA7
90
80
70
60
50
40
30
APPROXIMATE
20
THRESHOLD OF
HEARING FOR
CONTINUOUS
NOISE
10
63
125
250
BAND CENTER FREQUENCIES, Hz
NOTCH SPL(dB)
LINE
High
32
Medium1
31
Medium2
29
Low
28
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
500
1000
2000
4000
8000
NOTCH SPL(dB)
LINE
High
38
Medium1
35
Medium2
32
Low
28
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
500
1000
2000
4000
8000