2026-04-13T06:48:05Zhttps://recercat.cat/oai/request

oai:recercat.cat:10230/340722025-12-24T09:01:09Zcom_2072_6col_2072_452952

A system for sound analysis/transformation/synthesis based on a deterministic plus stochastic decomposition Serra, Xavier So -- Enregistrament i reproducció -- Tècniques digitals This dissertation introduces a new analysis/synthesis method. It is designed to obtain musically useful intermediate representations for sound transformations. The method’s underlying model assumes that a sound is composed of a deterministic component plus a stochastic one. The deterministic component is represented by a series of sinusoids that are described by amplitude and frequency functions. The stochastic component is represented by a series of magnitude-spectrum envelopes that function as a time-varying filter excited by white noise. Together these representations make it possible for a synthesized sound to attain all the perceptual characteristics of the original sound. At the same time the representation is easily modified to create a wide variety of new sounds. This analysis/synthesis technique is based on the short-time Fourier transform (STFT). From the set of spectra returned by the STFT, the relevant peaks of each spectrum are detected and used as breakpoints in a set of frequency trajectories. The deterministic signal is obtained by synthesizing a sinusoid from each trajectory. Then, in order to obtain the stochastic component, a set of spectra of the deterministic component is computed, and these spectra are subtracted from the spectra of the original sound. The resulting spectral residuals are approximated by a series of envelopes, from which the stochastic signal is generated by performing an inverse-STFT. The result is a method that is appropriate for the manipulation of sounds. The intermediate representation is very flexible and musically useful in that it offers unlimited possibilities for transformation. 2018-03-08T10:12:56Z 2018-03-08T10:12:56Z 1989 info:eu-repo/semantics/doctoralThesis info:eu-repo/semantics/publishedVersion Aquest document està subjecte a una llicència Creative Commons https://creativecommons.org/licenses/by-nc/3.0/es/ info:eu-repo/semantics/openAccess Stanford University