Computationally Efficient Music Synthesis - Methods and Sound Design

Abstract of the Master's Thesis

In this thesis, the design of a music synthesizer for systems suffering from limitations in computing power and memory capacity is presented. First, different possible synthesis techniques are reviewed and their applicability in computationally efficient music synthesis is discussed. In practice, the applicable techniques are limited to additive and source-filter synthesis, and, in special cases, to frequency modulation, wavetable and sampling synthesis.

Next, the design of the structures of the applicable techniques are presented in detail, and properties and design issues of these structures are discussed. A major implementation problem is raised in digital source-filter synthesis, where the use of classic waveforms, such as sawtooth wave, as the source signal is challenging due to aliasing caused by waveform discontinuities. Methods for existing bandlimited waveform synthesis are reviewed, and a new approach using polynomial bandlimited step function is presented in detail with design rules for the applicable polynomials. The approach is also tested with two different third-order polynomials. They reduce aliasing more at high frequencies, but at low frequencies their performance is worse than with the first-order polynomial. In addition, some commonly used sound effect algorithms are reviewed with respect to their applicability in computationally efficient music synthesis.

In many cases the sound synthesis system must be capable of producing music consisting of various different sounds ranging from real acoustic instruments to electronic instruments and sounds from nature. Therefore, the music synthesis system requires careful sound design. In this thesis, sound design rules for imitation of various sounds using the computationally efficient synthesis techniques are presented. In addition, the effects of the parameter variation for the design of sound variants are presented.

Keywords

sound synthesis, computer music, computational efficiency, synthesis algorithms, sound effects, sound design.

Files

• Thesis (PDF, 92 pages, 3.9 MB)
• Presentation slides (PDF, 6 pages, 208 kB)

Sound examples

• Slide 14:

  String, Pipe, Brass and Reed Instruments	Nylon Stringed Guitar
  Organs, Mallets and Bells	Percussive Organ
  Electronic Instruments and Synthetic Sounds	Electric Piano (FM)
  Percussion Instruments	Low Tom
  Sound Effects	Bird Tweet

• Slide 15:

  Changing the brightness	Acoustic Grand Piano	Bright Acoustic Piano
  Widening of the timbre	Marimba	Wide Marimba
  Adding power	Low Tom	Power Tom
  Adding reverberation	Low Tom	Room Tom

• Slide 18:

  MIDI-clip "Sultans of Swing", 18.5 s Played via computer sound card Played via a VLSI-chip model exploiting the presented sound design

All sound examples bundled as a zip-archive.