Larson Davis SoundExpert LxT, User Manual

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LxT Manual Glossary and Formulas
C
-
23
Sound Exposure (SE)
The total sound energy of the actual sound during a specific
time period. It is expressed in Pascal-squared seconds.
where p
A
is the instantaneous sound pressure and T
2
- T
1
is
the Measurement Duration (specific time period).
The LxT displays Sound Exposure as
E
X
, where X is the frequency weight-
ing ( X=A, C or Z ).
When applied to hearing damage potential, the equation is
changed to
where k is the Exposure Factor. See Exchange Rate.
Standard : ANSI S1.25.
Sound exposure and sound exposure level are calculated as
specified in IEC 61672-1.
The A-weighted sound exposure E
A
of a specified event is
represented by
where P
A
2 (t) is the square of the A-weighted instantaneous
sound pressure during an integration time starting at t
1
and
ending at t
2
.
The unit of A-weighted sound exposure is pascal-squared
seconds if A-weighted sound pressure is in pascals and
running time is in seconds. However it is sometimes
expressed in pascal-squared hours for measurements of
noise exposure in the workplace.
SE p
A
2
t
 
t d
T
1
T
2

=
SE p
A
2
t
   
k
t d
T
1
T
2

=
dt t p E
t
t
A
A
) (
2
1
2

