Using ISO 3382 measures, and their extensions, to evaluate acoustical conditions in concert halls

Application of the ISO 3382 standard can lead to the acquisition of large amounts of data describing conditions in a hall. The data could include the values of a number of measures at 6 or more octave band frequencies and for many combinations of source and receiver location. This paper discusses and gives examples of using this data to find important acoustical features. The amount of data can be reduced by calculating average values over the entire data set or for each sub-area of the hall. Various important spatial variations can often be better understood from plots of values versus source-receiver distance. The analysis approach will depend on the purpose of the study, which could be for comparisons with various criteria, for investigations of problems, or to better understand the acoustical properties of the hall. The significance of new measurements can be determined by comparing values: with proposed ideal criteria, with values in well-known halls, or with theoretical predictions. The importance of differences between two values should be considered in terms of published just noticeable differences for particular measures. Separately examining early-and late-arriving sound levels can be a useful diagnostic tool for better understanding the acoustical properties of halls.