This standard describes methods for measuring sound pressure
levels in the outdoor environment, taking into account the effects
of refraction due to wind and temperature gradients, the effects of
atmospheric turbulence, the effects of variable ground impedance,
and wind noise.
This standard assumes A-frequency weighting or the use of
octave, 1/3-octave, or narrow-band filters, but does not preclude
the use of other frequency weighting or other sound
This standard prescribes selected meteorological conditions
under which sound pressure level measurements shall be made.
Certain meteorological conditions are reproducible and correspond
to quite stable sound propagation conditions. These optimal
conditions yield reproducible measurements and allow the comparison
of sound pressure levels measured at different times.
The standard does not prescribe standardized receiver locations.
Sound pressure levels may be measured at receiver locations of
interest, within certain prescribed limits.
Measurement conditions shall be carefully documented and noted
in the report describing the sound pressure level measurements. The
measured sound pressure levels shall apply only to the stated
conditions and shall not represent the sound pressure levels under
other conditions, sites, receiver locations, or sources. In some
cases, guidance is provided to adjust the measured sound pressure
levels to reference conditions, other sites, or other receiver
This standard does not include procedures for measurement of
long-term, time-average environmental sound levels in a community
for environmental assessment or planning for compatible land
Sound pressure levels measured for determining the sound power
radiated by a source are not covered by this standard.
The purpose of this standard is to specify procedures for
measuring and reporting sound pressure levels from specifiC sources
outdoors and to specify a set of reproducible atmospheric
conditions to obtain reproducible measurements