مدت مواجهه در روز

تراز فشار به db

24 (hr/day)

80

16 (hr/day)

82

8 (hr/day)

85

4 (hr/day)

88

2 (hr/day)

91

1 (hr/day)

94

30 (Min/day)

97

15 (Min/day)

100

7.5 (Min/day)

103

3.75 (Min/day)

106

1.88 (Min/day)

109

0.94 (Min/day)

112

28.12 (sec/day)

115

14.06 (sec /day)

118

7.03 (sec /day)

121

3.52 (sec /day)

124

1.76 (sec /day)

127

0.88 (sec /day)

130

0.44 (sec /day)

133

0.22 (sec /day)

136

0.11 (sec /day)

139