Comparison of loudness calculation procedure results to equal loudness contours

Advances in the field of psychoacoustics have resulted in the development of more accurate models for the calculation of loudness as well as improved contours representing loudness perception. This study was undertaken to experimentally determine a "best use" stationary loudness model among the standardized methods available. To accomplish this, an investigative study was performed using pure tones at varying frequencies to identify the strengths and weaknesses of these loudness algorithms. The results of the investigation showed that with the recent update to the reference equal loudness contours, several of the models have become outdated in their performance. The recently revised ANSI S3.4:2007 model was shown to have the best correlation to the reference curves based on experimental measurements and was also the easiest to implement. It is recommended that the ANSI S3.4:2007 loudness model be used as the present day standard for calculation of stationary loudness.