Digital sampling instrument
AssigneeCreative Technology Ltd
InventorsDana C. Massie, David P. Rossum
Life of this patent
Estimating the term…
Abstract
An electronic music system which imitates acoustic instruments addresses the problem wherein the audio spectrum of a a recorded note is entirely shifted in pitch by transposition. The consequence of this is that unnatural formant shifts occur, resulting in the phenomenon known in the industry as "munchkinization." The present invention eliminates munchkinization, thus allowing a substantially wider transposition range for a single recording. Also, the present invention allows even shorter recordings to be used for still further memory improvements. An analysis stage separates and stores the formant and excitation components of sounds from an instrument. On playback, either the formant component or the excitation component may be manipulated.
Claims20
An apparatus for synthesis of sounds comprising:
- excitation generation means for generation of a long-term prediction coded excitation signal;
- means for inverse long-term prediction coding of said long-term prediction coded excitation signal to provide a decoded excitation signal having a pitch;
- means for pitch shifting said pitch of said decoded excitation signal to provide a pitch shifted excitation;
- and
- means for filtering said pitch shifted excitation with a formant filter.
An apparatus for generating a sound from an input signal having a formant spectrum and an excitation component, comprising:
- formant extraction means for extracting a formant filter spectrum from said input signal;
- filter spectrum inversion means for inverting said formant filter spectrum to produce an inverted formant filter;
- excitation extraction means for extracting said excitation component from said input signal by applying said inverted formant filter to said input signal to produce an extracted excitation component;
- excitation modification means for modifying said extracted excitation component to produce a modified excitation component;
- and
- synthesis means for using said modified excitation component and said formant filter spectrum to synthesize said sound.
A method for generating a sound from an input signal having a formant spectrum and an excitation component, comprising the steps of:
- extracting a formant filter spectrum from said input signal;
- inverting said formant filter spectrum to produce an inverted formant filter;
- extracting said excitation component from said input signal by applying said inverted formant filter to said input signal to produce an extracted excitation component;
- modifying said extracted excitation component to produce a modified excitation component;
- and
- using said modified excitation component and said formant filter spectrum to synthesize said sound.
A sound synthesizer apparatus comprising:
- a memory storing formant filter coefficients and an excitation component,
- said format filter coefficients having been derived by extracting a formant filter spectrum from an input signal,
- said excitation component having been derived by inverting said formant filter spectrum to produce an inverted formant filter and extracting said excitation component from said input signal by applying said inverted formant filter to said input signal;
- excitation modification means for modifying said excitation component to produce a modified excitation component;
- and
- synthesis means for using said modified excitation component and said formant filter spectrum to synthesize a sound.
Dependencies are inferred from the claim text.