This International Standard specifies all the information necessary to carry out efficiently and under standardized conditions the determination, declaration, and verification of the noise emission characteristics of rotating electrical machines. It specifies noise measurement methods that can be used, and specifies the operating and mounting conditions required for the test. Noise emission characteristics include the sound power level and emission sound pressure level. The determination of these quantities is necessary: — for comparing the noise emitted by machines; — to enable manufacturers to declare the noise emitted; and — for the purposes of noise control. The use of this International Standard as a noise test code ensures the reproducibility of the determination of the noise emission characteristics within specified limits determined by the grade of accuracy of the basic noise measurement method used. Noise measurement methods allowed by this International Standard are precision methods (grade 1), engineering methods (grade 2) and survey methods (grade 3). Methods of engineering grade (grade 2) are to be preferred. This International Standard is applicable to rotating electrical machines of any length, width or height.