Download A Virtual Tube Delay Effect A virtual tube delay effect based on the real-time simulation of acoustic wave propagation in a garden hose is presented. The paper describes the acoustic measurements conducted and the analysis of the sound propagation in long narrow tubes. The obtained impulse responses are used to design delay lines and digital filters, which simulate the propagation delay, losses, and reflections from the end of the tube which may be open, closed, or acoustically attenuated. A study on the reflection caused by a finite-length tube is described. The resulting system consists of a digital waveguide model and produces delay effects having a realistic low-pass filtering. A stereo delay effect plugin in P URE DATA1 has been implemented and it is described here.
Download Sound morphologies due to non-linear interactions : towards a perceptive control of environmental sound-synthesis processes This paper is concerned with perceptual control strategies for physical modeling synthesis of vibrating resonant objects colliding nonlinearly with rigid obstacles. For this purpose, we investigate sound morphologies from samples synthesized using physical modeling for non-linear interactions. As a starting point, we study the effect of linear and non-linear springs and collisions on a single-degreeof-freedom system and on a stiff strings. We then synthesize realistic sounds of a stiff string colliding with a rigid obstacle. Numerical simulations allowed the definition of specific signal patterns characterizing the non linear behavior of the interaction according to the attributes of the obstacle. Finally, a global description of the sound morphology associated with this type of interaction is proposed. This study constitutes a first step towards further perceptual investigations geared towards the development of intuitive synthesis controls.