Decomposition of steady state instrument data into excitation system and formant filter components

Ilia Bisnovatyi; Michael O’Donnell
DAFx-1999 - Trondheim
This paper describes a method for decomposing steady-state instrument data into excitation and formant filter components. The input data, taken from several series of recordings of acoustical instruments is analyzed in the frequency domain, and for each series a model is built, which most accurately represents the data as a source-filter system. The source part is taken to be a harmonic excitation system with frequency-invariant magnitudes, and the filter part is considered to be responsible for all spectral inhomogenieties. This method has been applied to the SHARC database of steady state instrument data to create source-filter models for a large number of acoustical instruments. Subsequent use of such models can have a wide variety of applications, including wavetable and physical modeling synthesis, high quality pitch shifting, and creation of “hybrid” instrument timbres.