ISO 532-2:2017 specifies a method for estimating the loudness and loudness level of stationary sounds as perceived by otologically normal adult persons under specific listening conditions. It provides an algorithm for the calculation of monaural or binaural loudness for sounds recorded using a single microphone, using a head and torso simulator, or for sounds presented via earphones. The method is based on the Moore-Glasberg algorithm.

NOTE 1 Issues of binaural calculations are discussed in Annex A.

NOTE 2 Users who wish to study the details of the calculation method can review or implement the source code, which is entirely informative and provided with ISO 532-2:2017 for the convenience of the user.

This method can be applied to tones, broadband noises and complex sounds with sharp line spectral components, for example transformer hum or fan noise.

NOTE 3 It has been shown (see Reference [15]) that this method provides a good match to the contours of equal loudness level as defined in ISO 226:2003 and the reference threshold of hearing as defined in ISO 389‑7:2005.

The evaluation of the harmful effect of sound events is outside the scope of ISO 532-2:2017.