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Slide 2 Sound Synthesis Part III: Distortion-based synthesis (FM & Waveshaping) Slide 3 Plan Distortion-based synthesis FM synthesis Waveshaping Matlab code for synthesis Example of synthesized composition (Risset) Summary Slide 4 Types of synthesis Sound Synthesis Additive synthesis Distortion techniques Subtractive synthesis Granular synthesis Analysis based Physical modelling Slide 5 Distortion (aka nonlinear) Synthesis Additive synthesis is powerful & flexible BUT requires many simple oscillators. Plethoric and non-intuitive controls on the sound spectrum. Using fewer oscillators, with more components. Complex spectra can be obtained by distorting simple oscillators. Slide 6 Plan Distortion-based synthesis FM synthesis Waveshaping Substractive synthesis Summary Slide 7 FM Synthesis Pioneered by John Chowning (1973) Alteration of distortion of the frequency of an oscillator in accordance with the amplitude of a modulating signal. Similar to Vibrato modulation, but using audible modulating frequency and larger width. Generate a large number of timbres easily controlled. Slide 8 FM Synthesis (2) Modulated frequency in fc-d Matlab Code Examples for all sounds are available here: http://info.ee.surrey.ac.uk/Personal/N.Pugeau lt/MediacastingL3_2012/http://info.ee.surrey.ac.uk/Personal/N.Pugeau lt/MediacastingL3_2012/ Parameters can be tweaked to evaluate their influence. Matlab is convenient for plotting results > spectrogram( y, ntime, noverlap, nfft, fs ) > spectrogram( y, 256, 250, 250, fs ) Can play sounds using the command: > sound( y, fs ) Slide 44 Plan Distortion-based synthesis FM synthesis Waveshaping Matlab code for synthesis Example of synthesized composition (Risset) Summary Slide 45 Plan Distortion-based synthesis FM synthesis Waveshaping Matlab code for synthesis Example of synthesized composition (Risset) Summary Slide 46 Additional Reading C. Dodge, C., & Jerse, T. A. (1997). Computer Music: Synthesis, Composition, and Performance. Schrimer, UK. (see chapters 5 and 6) Matlab examples for all sounds & instruments are available here: http://info.ee.surrey.ac.uk/Personal/N.Pug eault/MediacastingL3_2012/http://info.ee.surrey.ac.uk/Personal/N.Pug eault/MediacastingL3_2012/