Historical
ANSI/ASA S12.9-2013/Part 3
Quantities and Procedures for Description and Measurement of Environmental Sound - Part 3: Short-term Measurements with an Observer Present
The scope of this standard includes the measurement, with an observer present, of quantities such as equivalent-continuous sound pressure level or sound exposure from a specific source or sources at a specified location. These measurements require several minutes to several hours to perform; they take less than one day to perform. Measurements may be obtained with a standard frequency weighting, may be frequency filtered in a defined manner, or may be frequency filtered by octave band or fractional octave band filters. This standard specifies procedures to effectively eliminate, to the extent possible, the contributions of extraneous background sound from the source-specific measurements. Measurement procedures in this standard require the presence of an instrument operator and are not applicable to measurements by unattended instruments. This standard does not define specific measures or limits for environmental sounds or recommend measurement locations or durations.
Acoustical Society of America [asa]