This document specifies two methods for estimating the loudness and loudness level of sounds as perceived by otologically normal persons under specific listening conditions. The first method is intended for stationary sounds and the second method for arbitrary non-stationary (time-varying) sounds, including stationary sounds as a special case.
The methods can be applied to any sound recorded as single-channel measurements using a microphone,or as multi-channel measurements, for example by means of a head and torso simulator (see Annex D).
Since most important technical sounds are time-varying, a model of time-varying loudness is preferable.
