Standards for calculating loudness of stationary or timevarying sounds

摘要

For pure tones at 1 kHz with different levels loudness values from ANSI S3.4-2007 or DINrn45631 (1991) are essentially the same. Deviations of calculated values from loudness valuesrnexpected on the basis of subjective evaluations amount to a maximum of 5 % in line with thernaccuracy possible in loudness experiments.rnHowever, for pink noise of different levels, ANSI S3.4-2007 gives systematically higherrnloudness values than DIN 45631 (1991). The magnitude of the relative differences depends onrnlevel and reaches factors between 1.27 and 2.31 for the levels considered.rnInterestingly, when shifting the curve obtained for pink noise from ANSI S3.4-2007 by 5 dBrntowards higher levels, it almost coincides with the curve obtained from DIN 45631 (1991).rnTechnical sounds usually produce time-varying loudness functions which can be assessed usingrnDIN 45631/A1 (2008). More or less extreme examples are given for a planing machine and arnjackhammer.