scope:

This International Standard specifies the essential acoustical performance requirements of reference sound sources. It specifies procedures for calibrating a sound source intended for use as a reference sound source in terms of its sound power levels in octave and one-third octave bands and with frequency weighting A. To achieve uniform and accurate results, this international Standard requires that the calibration be performed in the acoustic environment provided by a hemi-anechoic room, i.e. free field over a reflecting plane. The reference sound source operates on the reflecting plane and radiates sound into the free field above the plane. It specifies the detailed procedures necessary to achieve the estimated calibration uncertainly given in table 1. This International Standard applies to a sound source which is manufactured for use as a reference sound source.