Page 92
Function
Equation
Equivalent
Continuous
C-weighted
Sound
Pressure Level
L
CeqT
20 log
⋅
1
T
t T
−
t
ξ
P
C
( )
2
ξ
( )
⌠
⌡
d
1
2
Po
⋅
dB
:=
L
CeqT
10 log
⋅
1
T
0
T
t
P
C
( )
2
t
( )
⌠
⌡
d
P
o
( )
2
⋅
dB
:=
ξ
is a dummy variable of time integration over the
averaging time interval ending at the time observation t
T is the averaging time interval
P
C
(
ξ
) is the instantaneous C-weighted sound pressure
P
o
is the reference sound pressure of 20µPa
In the equation above, the numerator of the argument of
the logarithm is the root-mean-square, frequency-weighted
sound pressure over averaging time interval T
Equivalent
Continuous
Z-weighted
Sound
Pressure Level
L
ZeqT
20 log
⋅
1
T
t T
−
t
ξ
P
Z
( )
2
ξ
( )
⌠
⌡
d
1
2
Po
⋅
dB
:=
L
ZeqT
10 log
⋅
1
T
0
T
t
P
Z
( )
2
t
( )
⌠
⌡
d
P
o
( )
2
⋅
dB
:=
ξ
is a dummy variable of time integration over the
averaging time interval ending at the time observation t
T is the averaging time interval
P
Z
(
ξ
) is the instantaneous Z-weighted sound pressure
P
o
is the reference sound pressure of 20µPa
In the equation above, the numerator of the argument of
the logarithm is the root-mean-square, frequency-weighted
sound pressure over averaging time interval T
