Download Sinusoidal Synthesis Method using a Force-based Algorithmm In this paper we propose a synthesis method using a force-based algorithm to control frequencies of multiple sine waves. In order to implement this synthesis method, we analyze an existing sound source using a fast Fourier transform (FFT). Spectral peaks which have large magnitudes are regarded as heavy partials and assigned large attractive forces. A few hundred sine waves with stationary amplitudes are placed in a frequency space on which forces generated in the analysis phase are applied. The frequencies of the partials gravitate to the nearest peak of the reference spectrum from the source sound. As more sine waves are combined at the large peaks, the sound synthesized by the partials gradually transforms into the reference spectrum. In order to prevent the frequencies of the partials from gravitating onto localized peaks, each partial is assigned a repulsive force against all others. Through successful control of these attractive and repulsive forces, roughness and speed variation of the synthesis can be achieved. Moreover, by increasing or decreasing the number of partials according to the total amplitude of the source sound, amplitude envelope following is achieved.
Download Real-Time Force-Based Sound Synthesis Using GPU Parallel Computing In this paper we propose a real-time sound synthesis method using a force-based algorithm to control sinusoidal partials. This synthesis method can generate various sounds from musical tones and noises with three kinds of intuitive parameters, which are attractive force, repulsive force and resistance. However, the implementation of this method in real-time has difficulties due to a large volume of calculations for manipulating thousands or more partials. In order to resolve these difficulties, we utilize a GPU-based parallel computing technology and precalculations. Since GPUs allowed us to implement powerful simultaneous parallel processing, this synthesis method is made more efficient by using GPUs. Furthermore, by using familiar musical features, which include MIDI input for playing the synthesizer and ADSR envelope generators for time-varying parameters, an intuitive controller for this synthesis method is accomplished.