This SAE Standard describes a method for determining the noise emitted to the environment by earthmoving machinery in terms of the a-weighted sound power level while the machine is working under dynamic test conditions.
SAE J2104-1991 history
1991SAE J2104-1991 Acoustics - Measurement of Exterior Noise Emitted by Earthmoving Machinery - Dynamic Test Conditions, Standard; June 1991 (ISO 6395)