Interestingly, it has also been found that a performer's movements can subtly shape the sound production. For instance, consider the following series of pictures:
|J.-G. Boisvert playing Praescio IV, by Bruce Pennycook at McGill University in 1999.|
In the case of the clarinet, bell-movement is the cause of amplitude modulations that are perceived as a subtle flanging effect. In fact, for a microphone placed in front of the clarinet, the interaction between the direct sound coming from the instrument and the first (floor) reflection can be modeled as two delay lines.
|Model for the influence of ancillary gestures in the resulting instrument sound (recorded by a microphone).||Mathematical representation.|
We have performed room response measurements in order to obtain the values for the model above. The folllwoing pictures show one of the measurements made at IRCAM, in Paris, France (Gerard Bertrand ins the technician).
|Various clarinet angles used in the measurement.||Gerard Bertrand and the device used for the room measurements at IRCAM.|
The resulting delay difference is dependent on the position of the bell with respect to a microphone or listener. Depending on the position of the instrument and of the microphone, delay differences between 2 and 5 ms can be obtained dependent on the clarinet angle.
|Results of measurements (gains and delays).|
Therefore, a sort of gesturally-controlled flanger can be obtained, the delay being a function of the clarinet angle.
An example of application was produced by applying the effect of performer movements onto a clarinet sound recorded in an anechoic chamber. This sound file presents a (very) simple simulation with the anechoic sound plus several repetitions of it where simulations of one-dimensional movements were created (using a slider) in Max/MSP. The simulations run from simple to more complex movements.
This part of the research is performed in collaboration with Prof. Philippe Depalle.