Objective measures for evaluating tonal balance of sound fields

摘要

The purpose of this study is to derive objective measures that can accurately represent the characteristics of a sound field regarding the tonal balance corresponding to our sense of hearing. Two types of listening test were conducted in the form of paired comparison, in which subjects were tested using sound fields produced by convoluting anechoic music sources with impulse responses. In the first listening tests, impulse responses were calculated theoretically for a simple structure of sound field consisting of a direct sound and reflections, and in the second tests, impulse responses were measured at various seats of concert halls. In the latter case, impulse responses that give almost the same distinctness were used in the listening tests. From this investigation, it is found that one objective measure named deviation of level (DL) is a possible effective measure for evaluating the tonal balance of sound fields. The index DL is calculated from data based on the logarithmic scale in both the frequency and magnitude.