Dynamic Excitation Impulse Modification as a Foundation of a Synthesis and Analysis System for Wind Instrument Sounds

Abstract

The Variophon is a wind synthesizer that was developed at the Musicological Institute of the University of Cologne in the 1970/80ies and was at that time based on a completely new synthesis principle: the pulse forming process. The central idea of that principle is that every wind instrument sound can basically be traced back to its excitation pulses, which independently of the fundamental always act upon the same principles. In a recent project, supported by the German Research Foundation (DFG), the synthesis method of excitation impulse modification has been transferred to a digital platform.

The aim of the software-based modelling is twofold: creating an experimental system for analyzing and synthesizing (wind) instrument sounds, as well as building a synthesizer, that would be an alternative to comparable wind instrument synthesis applications. On the one hand this sound synthesis technique accounts for the place where the sound is generated, on the other hand only a single breath controller is required to produce all the sound-nuances that are possible on a real instrument.

First of all the analogue circuits of the different instrument modules of the Variophon will be mapped onto a digital representation by means of the analogue circuit simulation software LTSpice. After the original algorithms have been analysed, the Digital Variophon will be rebuilt in the modular Reaktor environment by Native Instruments (NI). Finally the experimental system will be validated by means of a prototypical perception experiment.