| Résumé |
Some recent works dealing with the loudness of dynamic sounds showed that sounds that increase continuously in level (up-ramps) are perceived with a greater loudness change or global loudness than opposite down-ramps,although they only differ in direction. The understanding of sensory and cognitive mechanisms involved in the loudness of increasing and decreasing sounds is still a burning issue. In all the studies reporting this effect, estimations were made directly at the end of one ramp in single-stimulus paradigms or using a short ISI (Inter Stimulus Interval) between two ramps in paired-stimulus paradigms. In the present study, global loudness was measured using a paired comparison method. The influence of the ISI was examined for ramps that differed in direction, dynamic and maximum level. Results show that judgments (1) are dominated by the maximum level of a ramp, (2) are mainly independent of the direction of the first ramp of the pair and that, (3) asymmetries between up-ramps and down-ramps are reduced with a longer ISI. The Neuhoff evolutionary hypothesis explaining these asymmetries by an overestimation of up-ramps is discussed in regard to these results. |
