Music – Instruments – Electrical musical tone generation
Patent
1997-05-01
1998-04-21
Shoop, Jr., William M.
Music
Instruments
Electrical musical tone generation
84624, 84629, G10H 112, G10H 500
Patent
active
057407169
ABSTRACT:
A sound synthesis system employs a variable-length delay line whose length is modulated at a frequency that is close to the fundamental frequency of the delay line. By modulating the length of the delay line at a frequency close to the fundamental frequency of the delay line, a new class of sounds is generated. A delay line length modulator produces a periodic modulation signal whose frequency is close to the fundamental frequency of the delay line. The length of the delay line is modulated in accordance with the modulation signal, thereby causing a variable pitch shifting effect in the waveform produced by the delay line structure. Since the length of the delay line is modulated at a frequency close to the average loop frequency, part of the waveform stored by the delay line is time-compressed and the other part is expanded. The waveform's shape changes smoothly so that the compressed part of the waveform is pitched-shifted upwards, and the expanded part is pitch-lowered. A simultaneous upward and downward shift in the spectrum of the waveform stored by the delay line results, generating musically intriguing sounds. In one embodiment, a regeneration filter introduces an instability into the delay line's feedback loop at a frequency of half the sampling rate. This introduces additional energy into the system which causes the waveform in the delay line to regenerate, thereby increasing the length of time that sound effects are generated after the introduction of an excitation pulse.
REFERENCES:
patent: 4622877 (1986-11-01), Strong
patent: 4649783 (1987-03-01), Strong et al.
patent: 5223653 (1993-06-01), Kunimoto et al.
patent: 5308918 (1994-05-01), Yamauchi et al.
patent: 5496964 (1996-03-01), Suzuki
patent: 5500486 (1996-03-01), Smith, III
patent: 5578780 (1996-11-01), Wachi
patent: 5641931 (1997-06-01), Ogai et al.
Donels Jeffrey W.
Shoop Jr. William M.
The Board of Trustees of the Leland Stanford Juior University
Williams Gary S.
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