The Role of Attack Transients in Timbral Brightness Perception
* Presenting author
Evidence from acoustical modeling and multidimensional scaling of brightness dissimilarity ratings of natural instrumental sounds [Saitis & Siedenburg, in prep.] suggest at least two acoustical properties of tones to play a role in the perception of timbral brightness: a) the spectral energy distribution, and b) the attack time and/or asynchrony in the rise of harmonics. To further investigate the role of these cues in timbral brightness perception with highly controlled stimuli, 40 musically experienced listeners will perform a MUSHRA-like task involving synthetic harmonic complexes varying along three parameters: spectral centroid, attack time, and fluctuation of spectral centroid over the first 100 ms. The latter models the progressive expansion of the spectrum toward the higher harmonics. It is hypothesized that two sounds with same spectral centroid values but different attack times will be perceived to differ in brightness, with faster attacks leading to brighter sounds. Similarly, two sounds with same spectral centroids and attack times but different “arrival times” for the higher harmonics will vary in perceived brightness: the sooner higher harmonics appear, the brighter the sound. Overall, this experiment will thus help to clarify the relation between two major factors in timbre perception: onset and spectral energy distribution.