The temporal weighting of loudness: effects of the level profile

Abstract

In four experiments, we studied the influence of the level profile of time-varying sounds on temporal perceptual weights for loudness. The sounds consisted of contiguous wideband noise segments on which independent random-level perturbations were imposed. Experiment 1 showed that in sounds with a flat level profile, the first segment receives the highest weight (primacy effect). If, however, a gradual increase in level (fade-in) was imposed on the first few segments, the temporal weights showed a delayed primacy effect: The first unattenuated segment received the highest weight, while the fade-in segments were virtually ignored. This pattern argues against a capture of attention to the onset as the origin of the primacy effect. Experiment 2 demonstrated that listeners adjust their temporal weights to the level profile on a trial-by-trial basis. Experiment 3 ruled out potentially inferior intensity resolution at lower levels as the cause of the delayed primacy effect. Experiment 4 showed that the weighting patterns cannot be explained by perceptual segmentation of the sounds into a variable and a stable part. The results are interpreted in terms of memory and attention processes. We demonstrate that the prediction of loudness can be improved significantly by allowing for nonuniform temporal weights.

Temporal loudness weights for sounds with increasing and decreasing intensity profiles

“…On the one hand, clear primacy and recency effects were found for flat level profile sounds. Although the recency effect was greater in our experiment than in previous studies, most likely due to the fact that the sounds used were longer, these results broadly support the trends observed concerning this type of stimulus (Pedersen and Ellermeier, 2008;Oberfeld and Plank, 2011). On the other hand, this study used a molecular approach to examine in particular whether the temporal weights of high-level components of increasing sounds could be greater than those of decreasing sounds.…”

“…A common effect of saliency for the two profiles was obtained, where the most intense segments received exclusive attention from the listeners. This effect was also pointed out in other studies (Lutfi and Jesteadt, 2006;Pedersen and Ellermeier, 2008;Oberfeld and Plank, 2011) that were interested in temporal weighting of non-steady profiles, and it was defined, as mentioned above, as the "level dominance" effect.…”

“…We opted for a logistic regression analysis for weights estimation and employed the same decision model as in previous studies (Pedersen and Ellermeier, 2008;Oberfeld and Plank, 2011). Regressions were conducted using R (R Core Team, 2013) separately for each listener, each intensity profile and each distribution (low/high).…”

“…In studies with non-steady profile sounds, a so-called "level dominance" effect was observed, the initial high-level components receiving greater attention from the listeners (Lutfi and Jesteadt, 2006;Oberfeld and Plank, 2011).…”

“…So far, temporal weights of loudness have been assessed mainly for sounds with flat intensity profiles (e.g., Pedersen and Ellermeier, 2008;Oberfeld and Plank, 2011;Oberfeld et al, 2012). Using experimental designs based on molecular a) Author to whom correspondence should be addressed.…”