Temporal weighting of loudness: Comparison between two different psychophysical tasks.

Abstract

Psychophysical studies on loudness have so far examined the temporal weighting of loudness solely in level-discrimination tasks. Typically, listeners were asked to discriminate hundreds of level-fluctuating sounds regarding their global loudness. Temporal weights, i.e., the importance of each temporal portion of the stimuli for the loudness judgment, were then estimated from listeners' responses. Consistent non-uniform "u-shaped" temporal weighting patterns were observed, with greater weights assigned to the first and the last temporal portions of the stimuli, revealing significant primacy and recency effects, respectively. In this study, the question was addressed whether the same weighting pattern could be found in a traditional loudness estimation task. Temporal loudness weights were compared between a level-discrimination (LD) task and an absolute magnitude estimation (AME) task. Stimuli were 3-s broadband noises consisting of 250-ms segments randomly varying in level. Listeners were asked to evaluate the global loudness of the stimuli by classifying them as "loud" or "soft" (LD), or by assigning a number representing their loudness (AME). Results showed non-uniform temporal weighting in both tasks, but also significant differences between the two tasks. An explanation based on the difference in complexity between the evaluation processes underlying each task is proposed.