Effect of time distribution of energy on loudness evaluation
Résumé
Most works on loudness have been done for stationnary sounds. However, environnemental sounds are usually temporally variable, and memory effects could be important in loudness evaluation of long-lasting dynamics sounds. Loudness of one-minute sounds containing a local dominating peak of energy has been measured. The sounds differed only by the temporal position of the peak. The influence of peak location on the global loudness judgement has been evaluated. The global loudness was first evaluated using magnitude estimation. In spite of the expectation, mean estimations were the same for all sounds whatever the peak distribution. In a second experiment, the subject had to judge the loudness, using a cross-modality matching. He had to match 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-modality matching. This global estimation was made either just after the sound or after a pause of one minute. During the pause, the subject had to execute a distractive task. Relations between global and continuous judgement are discussed. The study can help to design a model of the loudness of temporally variable sounds.