Perceptual Evaluation of Rolling Sound Synthesis

Abstract

Three listening tests were conducted to perceptually evaluate different versions of an ew real-time synthesis approach for sounds of sustained contact interactions. This study aims to identify the most effective algorithm to create ar ealistic sound for rolling objects. In Experiment 1a nd 2, participants were asked to rate the extent to which 6different versions sounded likerolling sounds. Subsequently,inExperiment 3, participants compared the 6versions best rated in Experiment 1and 2, to the original recordings. Results are presented in terms of both statistical analysis of the most effective synthesis algorithm and qualitative user comments. On methodological grounds, the comparison of Experiments 1, 2and 3highlights major differences between judgments collected in reference to the original recordings as opposed to judgments based on memory representations of rolling sounds. PACS no. 43.66.Lj, 43.75.Zz Received16September 2010, accepted 15 May 2011. * currently at the School of Computing at Dublin City University. † currently at IRCAM, Paris. 1 This study waspart of alarger research project entitled "Haptics, Sound and Interaction in the Design of Enactive Interfaces". This collaborative project concerned the areas of sound synthesis and interface design, haptic devices, perception and cognition. 840 ©S.Hirzel Verlag · EAA Murphy et al.:R olling sound synthesis ACTA ACUSTICA UNITED WITH ACUSTICA Vol. 97 (2011)

Intuitive Control of Rolling Sound Synthesis

“…concluded that frequency dependent comb filters added more realism when simulating a ball approaching the edge of a plate. This was confirmed thanks to perceptual experiments by Murphy et al [29].…”

“…Hence, we simulate the reflection of the four first order images for a square plate, depending on a chosen listening point on the plate, on the ball's position and on the first natural frequency of the plate. As already pointed out by Murphy et al [29], this effect enhance the sensation of the ball's displacement.…”

“…This effect can be observed as varying ripples in the time-frequency representation of rolling sounds and is due to the interference between the sound generated at the point of contact between the ball and the plate and the sound reflected at the edges of the plate [33]. Murphy et al [29] performed a series of perceptual experiments to judge the quality of the analysis-synthesis algorithm described in [22]. In a first experiment, the listeners described the rolling sounds as "static".…”

A Synthesis Model With Intuitive Control Capabilities for Rolling Sounds

“…Verbal descriptors for rollingness along the slider were used as in [43], from Not at all like rolling (0), A little bit like rolling (25), Somewhat like rolling (50), Close to rolling (75) to Exactly like rolling (100). Before the evaluation session, 6 different sounds were presented in a random order to familiarize the listener with the sounds.…”

“…sound examples on the companion web page). As pointed out by some authors [43], [50], the rolling sound could be rendered more realistic by taking into account additional effects such as the amplitude variation of the modes over time when the ball is rolling on a finite surface. This effect is currently being implemented in the synthesizer using a comb-filtering process.…”