The psychomechanics of simulated sound sources: material properties of impacted thin plates.
Sounds convey information about the materials composing an object. Stimuli were synthesized using a computer model of impacted plates that varied their material properties: viscoelastic and thermoelastic damping and wave velocity (related to elasticity and mass density). The range of damping properties represented a continuum between materials with predominant viscoelastic and thermoelastic damping (glass and aluminum, respectively). The perceptual structure of the sounds was inferred from multidimensional scaling of dissimilarity judgments and from their categorization as glass or aluminum. Dissimilarity ratings revealed dimensions that were closely related to mechanical properties: a wave-velocity-related dimension associated with pitch and a damping-related dimension associated with timbre and duration. When asked to categorize sounds, however, listeners ignored the cues related to wave velocity and focused on cues related to damping. In both dissimilarity-rating and identification experiments, the results were independent of the material of the mallet striking the plate (rubber or wood). Listeners thus appear to select acoustical information that is reliable for a given perceptual task. Because the frequency changes responsible for detecting changes in wave velocity can also be due to changes in geometry, they are not as reliable for material identification as are damping cues.
McAdams
Stephen
S
Centre for Interdisciplinary Research in Music Media and Technology, Schulich School of Music, McGill University, 555 Sherbrooke Street West, Montreal, Quebec H3A 1E3, Canada. smc@music.mcgill.ca
Roussarie
Vincent
V
Chaigne
Antoine
A
Giordano
Bruno L
BL
D000161:Acoustic Stimulation; D000162:Acoustics / Q000295:instrumentation*; D000328:Adult; D001307:Auditory Perception; D003463:Cues; D004548:Elasticity; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009038:Motion; D011312:Pressure; D011571:Psychoacoustics; D013016:Sound; D013018:Sound Spectrography; D013997:Time Factors; D014732:Vibration; D014783:Viscosity; D055815:Young Adult