A critical analysis of loudness calculation methods

Authors

  • Jeff J. Defoe Mechanical, Automotive and Materials Engineering, University of Windsor, 401 Sunset Ave., Windsor, Ont.
  • Colin J. Novak Mechanical, Automotive and Materials Engineering, University of Windsor, 401 Sunset Ave., Windsor, Ont.
  • Helen J. Ule Mechanical, Automotive and Materials Engineering, University of Windsor, 401 Sunset Ave., Windsor, Ont.
  • Robert G. Gaspar Mechanical, Automotive and Materials Engineering, University of Windsor, 401 Sunset Ave., Windsor, Ont.

Keywords:

Computation theory, Computer simulation, Computer software, Graphic methods, Numerical analysis, Signal filtering and prediction, Loudness, Pink noise, Psychoacoustic metric, Sound stimulus

Abstract

The physical meaning and methods of determining loudness were reviewed Loudness is a psychoacoustic metric which closely corresponds to the perceived intensity of a sound stimulus. It can be determined by graphical procedures, numerical methods, or by commercial software. These methods typically require the consideration of the 1/3 octave band spectrum of the sound of interest. The sounds considered in this paper are a 1 kHz tone and pink noise. The loudness of these sounds was calculated in eight ways using different combinations of input data and calculation methods. All the methods considered are based on Zwicker loudness. It was determined that, of the combinations considered, only the commercial software dBSonic and the loudness calculation procedure detailed in DIN 45631 using 1/3 octave band levels filtered using ANSI S1.11-1986 gave the correct values of loudness for a 1 kHz tone. Comparing the results between the sources also demonstrated the difference between sound pressure level and loudness. It was apparent that the calculation and filtering methods must be considered together, as a given calculation will produce different results for different 1/3 octave band input. In the literature reviewed, no reference provided a guide to the selection of the type of filtering that should be used in conjunction with the loudness computation method.

Additional Files

Published

2007-03-01

How to Cite

1.
Defoe JJ, Novak CJ, Ule HJ, Gaspar RG. A critical analysis of loudness calculation methods. Canadian Acoustics [Internet]. 2007 Mar. 1 [cited 2024 Nov. 2];35(1):25-33. Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/1869

Issue

Section

Technical Articles

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