Scanned Synthesis is a new synthesis technique developed by Bill Verplank, Max Mathews and Rob Shaw at Interval Research between 1998 and 2000.
"It has all the potential to, and we believe it will, become as important as existing methods such as wave table synthesis, additive synthesis, FM synthesis, and physical modeling".
Max Mathews and Bill Verplank
As of today, this new technique is only available through Csound using the opcodes developed by Paris Smaragdis.
Perry Cook and Richard Boulanger also worked as consultants and sound designers for Interval Research while the algorithm was developed.
Check out Dr. Boulanger's tutorial for more info.
Also see the license at the bottom of this page.
|by Max Mathews and Bill Verplank
from their recent lecture tour [Stanford, CNMAT, MIT, Berklee, Dartmouth]
Scanned synthesis involves a slow dynamic system whose frequencies of vibration are below about 15 hz. The system is directly manipulated by motions of the performer. The vibrations of the system are a function of the initial conditions, the forces applied by the performer, and the dynamics of the system. Examples include slowly vibrating strings, two dimensional surfaces obeying the wave equation, and a waterbed. We have simulated the string and surface models on a computer. Our waterbed model is purely conceptual.
The ear cannot hear the low frequencies of the dynamic system. To make audible frequencies, the "shape" of the dynamic system, along a closed path, is scanned periodically. The "shape" is converted to a sound wave whose pitch is determined by the speed of the scanning function. Pitch control is completely separate from the dynamic system control. Thus timbre and pitch are independent. This system can be looked upon as a dynamic wave table controlled by the performer.
The psychophysical basis for Scanned Synthesis comes from our knowledge about human auditory perception and human motor control abilities. In the 1960's Risset showed that the spectra of interesting timbres must change with time. We observe that musically interesting change rates are less than about 15 hz which is also the rate humans can move their bodies. We have named these rates Haptic rates.
We have studied Scanned Synthesis chiefly with a finite element model of a generalized string. Cadoz showed the musical importance of finite element models in the 1970s. Our models differ from Cadoz's in our focus on slow (haptic) vibration frequencies. Our finite element models are a collection of masses connected by springs and dampers. They can be analyzed with Newton's laws. We have generalized a traditional string by adding dampers and springs to each mass. All parameters--mass, damping, earth spring strength and string tension--can vary along the string. The performer manipulates the model by pushing or hitting different masses and by manipulating parameters.
We have already synthesized rich and interesting timbres and we have barely started to explore the range of possibilities in our present models. Many other different models can be conceived. We find the prospects exciting.
|Scanned Synthesis Opcodes:
scansyn.c, scansyn.csd, scansyn.h and related files are Copyright, 1999 by Interval Research.
Permission to use, copy, or modify these programs and their documentation for educational and research purposes only and without fee is hereby granted, provided that this copyright and permission notice appear on all copies and supporting documentation. For any other uses of this software, in original or modified form, including but not limited to distribution in whole or in part, specific prior permission from Interval Research must be obtained. Interval Research makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty.
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[+] scanned.zip 235Kb