Comparative study of a proposed time varying loudness standard for common sounds.

Abstract

Several calculation procedures exist and are standardized for the determination of loudness of steady sounds. While loudness models for unsteady sounds do presently exist, they differ in their outcomes and have not been yet sufficiently validated using round robin or other appropriate evaluation methodology. Recently, the Deutsches Institut fur Normung (DIN) announced that it will soon issue a new standard describing a method for calculation of loudness of time-varying sounds. However, the DIN 45631-A1 takes a less common approach in that it does not fully describe a methodology to calculate the unsteady loudness. It instead offers a more general procedure along with open-ended checks and balances for verifying the progress through the various calculation steps. The caveat of this is that while conditions specified by this standard may be satisfied, varying results may be achieved due to the procedures’ open architecture. Conversely, the checks and balances may be enough such that identical results are achieved for the same sounds. This study investigates several commercial applications using this standard and compares their results for several common inputs. The results of the study will be discussed in terms of the extent to which compliance with DIN 45631-A1 results in identical loudness scores.