Some factors influencing loudness asymmetries between rising and falling-intensity stimuli
Résumé
Previous research demonstrated that the loudness asymmetry between 1-kHz rising and fallingintensity
tones is a robust phenomenon, whose origins still remain unclear. In the present study, this phenomenon was
further examined as a function of two stimuli characteristics: the spectral content and the intensity-region. In a first
experiment, the global loudness of rising and falling-intensity sounds with various spectral contents (pure tones from
250 Hz to 8 kHz and broadband noises) presented in different intensity-regions (from [50-65 dB SPL] to [70-85 dB
SPL]) was assessed in an absolute magnitude estimation task. Significant asymmetries were found for tones at all
frequencies, but not for broadband noises. In addition, a significant interaction between the stimulus direction and the
intensity-region was observed for both tones and noises. This interaction was further examined in a second
experiment using an adaptive loudness-matching procedure. Although greater asymmetries were again observed for
tones, significant asymmetries were found for noises as well. Furthermore, the size of the asymmetries was
significantly decreased with the intensity-region when the pairs were composed of rising followed by falling stimuli.
These results are discussed in the light of recent physiological and neuroscience studies conducted with this type of
stimuli.