Spectral modeling synthesis (SMS) is an acoustic modeling approach for speech and other signals. SMS considers sounds as a combination of harmonic content and noise content. Harmonic components are identified based on peaks in the frequency spectrum of the signal, normally as found by the short-time Fourier transform. The signal that remains following removal of the spectral components, sometimes referred to as the residual, is then modeled as white noise passed through a time-varying filter. The output of the model, then, are the frequencies and levels of the detected harmonic components and the coefficients of the time-varying filter.
![](http://upload.wikimedia.org/wikipedia/commons/1/15/Spectrum_Modeling_Synthesis_overview_%28based_on_Curtis_Roads_1996%2C_Fig.4.23%29.jpg)
Intuitively, the model can be applied to many types of audio signals. Speech signals, for example, include slowly changing harmonic sounds caused by vibration of the vocal cords plus wideband, noise-like sounds caused by the lips and mouth. Musical instruments also produce sounds containing both harmonic components and percussive, noise-like sounds when the notes are struck or changed.
See also
editReferences
edit- Serra, Xavier (2003). "Spectral Modeling Synthesis: Past and Present" (PDF). p. 20. Retrieved May 11, 2010.
- Serra, Xavier. "Spectral Modeling Synthesis Tools". Retrieved May 11, 2010.
- Smith III, Julius O. (28 December 2005). "Spectral Modeling". Retrieved April 19, 2008.
- Roads, Curtis (1996). "Figure 4.23: Overview of spectrum modeling synthesis. ...". The Computer Music Tutorial. MIT Press. p. 153. ISBN 978-0-262-68082-0.
- Bonada, J.; Loscos, A.; Cano, P.; Serra, X.; Kenmochi, H. (2001). "Spectral Approach to the Modeling of the Singing Voice". In Proc. of the 111th AES Convention. CiteSeerX 10.1.1.75.2357.