A Percussive Sound Synthetizer Based on Physical and Perceptual Attributes
Authors: Aramaki M., Kronland-Martinet R., Voinier T., Ystad S.
Publication Date: June 2006
Journal: Computer Music Journal (vol. 30(2), pp. 32-41, 2006)
Tags: Sound Design
The sounds below have been synthetized in real time, using the MAX/MSP instrument described in the paper.
Simulation of the material contribution
By simply filtering a white noise, sounds corresponding to impacts on various materials can be designed. Depending on the evolution speed of the time-varying filter, the sound seems either “metallic” or “muffled”:
Effect of modal contributions
From a mechanical point of view, modes are strongly dependant on the geometry of the structure. From a signal point of view, modes correspond to mono-component contributions. By simply adding one sinusoidal component to the strongly damped noise (sound example 1), one can either simulate large or small sounding woods:
Two ways of addying modal contributions
As discussed in the paper, modal contributions can be obtained in two main ways. The first one consists in summing up deterministic components (sinusoidal waves) whereas the second uses narrow band-pass filtered versions of the entrance noise. As a result, the second approach leads to a better fusion between the noisy and the modal parts of the sound.
The synthesized sounds below are obtained using five modes.
Some examples of impacted sounds generated by the model
Simulation of the dynamic of the impact
The strength of the impact is correlated to the amount of energy given to the sounding structure. As a consequence, the stronger the impact, the richer the sound. These dynamical characteristics are simulated by controling a low pass filter bandwidth by the impact force.
A crucial aspect of the mapping – the tuning
The pitch of complex sounds still is an open issue. As an approach, we proposed to tune the impacted sounds by considering the modal components as a cluster of notes. Sounds can then be tuned by associating musical chords to sounds. These chords are defined by the tonic notes, the harmonic structures (major, minor, 7th, 9th, diminished, …) and their inversions.
Control of the material
Morphing effects simulating continuous transitions between two materials can be obtained by interpolating the synthesis parameters. These sound examples are currently used in neurophysiological experiments to study the categorization process of impacted materials