Title

Evaluation of loudness calculation techniques with applications for product evaluation

Date of Award

2007

Degree Type

Thesis

Degree Name

M.A.Sc.

Department

Mechanical, Automotive, and Materials Engineering

Rights

CC BY-NC-ND 4.0

Abstract

Methods of calculating steady loudness were examined. Loudness has been characterised as a psychoacoustic metric that closely matches the perception of sound intensity. Seven loudness model and four types of frequency filtering were considered, via the loudness levels of 80 dB tones over a range of frequencies. The loudness levels obtained from all combinations of the loudness models and filtering techniques were compared with the values from ISO 226-2003, an equal-loudness level standard. Glasberg and Moore's 2006 loudness model using FFT-based third-octave band filtering was determined to be the most suitable combination for general use. The criticality of setting full-scale sound pressure levels as close to the measured levels as possible was demonstrated. Jury tests were performed for product sounds, in which both loudness and overall acceptability were evaluated. It was found that calculated and subjective loudness agreed well but that loudness was not the dominant sensation in acceptability determination.