Effect of time distribution of energy on loudness evaluation

Abstract

Most work on loudness have been done on stationary sounds. However, environmental sounds are usually temporally variable, and memory effects could be important in loudness evaluation of long-lasting dynamic sounds. The loudness of one-minute sounds containing a local dominating peak of energy was measured. The sounds differed only by the temporal position of the peak. The influence of peak location on the global loudness judgment was evaluated. The global loudness was first evaluated using magnitude estimation. Contrary to expectations, mean estimations were the same for all sounds regardless of peak distribution. In a second experiment, subjects had to judge the loudness, using cross-modal matching. They matched the size of a circle on a computer screen with the loudness of the sound. At the end of the signal, a global estimation was also made using the same cross-modal matching paradigm. This global estimation was made either just after the sound or after a pause of one minute. During the pause, the subject had to perform a distracting task. Relations between global and continuous judgments are discussed. The study can help to design a model of the loudness of temporally variable sounds.