Pitch Strength and Asymmetry in Global Loudness between Rising-and Falling- Intensity Sounds

A sound is judged as overall louder if it increases rather than if it decreases in level over time; this is the so-called "asymmetry in global loudness". Several studies have shown that this effect is larger for pure tones than for broadband noises. Results of a previous study suggested that this difference is probably not related to the spectral width of the sounds per se, but by whether the sounds elicit a sensation of pitch or not. Based on the well-established finding that loudness and pitch interact with each other-e.g. a pure-tone that only increases/decreases in level is perceived as increasing/decreasing in pitch-we wondered whether this could explain why stronger asymmetries are found for tones vs. broadband noises. We hypothesized that the combination of loudness and pitch variations may reinforce the asymmetry in global loudness for sounds that elicit pitch. To test this hypothesis, we measured in this study the exact relationship between the size of the asymmetry in global loudness and sound's pitch using sounds whose pitch strength relative to the noise percept can be varied by modifying parameters (iterated ripple noises, bandpass noises), thus asymmetry in global loudness and pitch strength can be compared. Number of words in abstract: 198