Parametric signal modeling musical synthesizer
AssigneeEuPhonics, Incorporated
InventorsEric Lindemann, Jeffrey Barish
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Abstract
A parametric signal modeling musical tone synthesizer utilizes a multidimensional filter coefficient space consisting of many sets of filter coefficients to model an instrument. These sets are smoothly interpolated over pitch, intensity, and time. The filter excitation for a particular note is derived from a collection of single period excitations, which form a multidimensional excitation space, which is also smoothly interpolated over pitch, intensity and time. The synthesizer includes effective modeling of attacks of tones, and the noise component of a tone is modelled separately from the pitched component. The input control signals may include initial pitch and intensity, or the intensity may be time-varying. A variety of instruments may be specified.
Claims48
An electronic musical tone generator for generating an electrical output signal representing a musical tone in response to an input control signal, said musical generator comprising:
- an excitation signal generator responsive to said input control signal for generating an excitation signal;
- and
- a formant filter generator responsive to said input control signal for generating a time varying formant filter for filtering said excitation signal in a time varying manner to create the output tone signal;
- wherein said formant filter generator includes
- instrument parameter memory means for storing a plurality of sets of filter coefficients;
- intermediate parameter set generation means for deriving an intermediate filter coefficient set by interpolating between at least two of the sets of filter coefficients stored in instrument parameter memory based upon said input control signal;
- and
- time varying parameter generation means for interpolating within said intermediate filter coefficient set to generate said time varying formant filter.
An electronic musical tone generator for generating an output tone signal representing a musical tone in response to an input control signal representing desired pitch, said musical generator comprising:
- an excitation signal generator responsive to said input control signal for generating an excitation signal;
- said excitation signal generator including
- a multidimensional table oscillator memory for storing sets of oscillator data;
- an oscillator selector and interpolator for selecting at least two of the sets of oscillator data according to said control signal and interpolating between said sets of oscillator data to form an intermediate oscillator data table;
- and
- a table lookup oscillator for reading out data from the intermediate oscillator data table over time;
- and
- a formant filter generator responsive to said input control signal for generating a formant filter for filtering said excitation signal in a time varying manner to create the pitched signal;
- said formant filter generator including
- a multidimensional filter coefficient set table memory for storing sets of filter coefficients;
- a filter coefficient sequencer and interpolator for selecting at least two of the sets of filter coefficients according to said control signal and interpolating between them to form a variable rate decimated filter coefficient sequence;
- and
- a time varying filter generator for interpolating among the coefficients forming the decimated filter coefficient sequence over time to generate a series of filter coefficient sets for use in creating said formant filter.
A method for generating a musical tone in response to an input control signal, comprising the steps of:
- interpolating between data stored in an oscillator data table memory based upon the input control signal to generate an excitation signal;
- interpolating between sets of filter coefficients stored in a filter coefficient table memory based upon the input control signal to generate an intermediate filter coefficient set;
- interpolating within the intermediate filter coefficient set to generate a formant filter;
- and
- filtering the excitation signal with the formant filter to generate a tone.
An electronic musical tone generator for generating an electrical output signal representing a musical tone in response to an input control signal, comprising:
- an oscillator table memory for storing a plurality of oscillator tables;
- means for generating an excitation signal, including
- means for selecting and interpolating between at least two oscillator tables stored in the oscillator table memory, based upon the input control signal, to form a new oscillator table, and
- means for generating an excitation signal based upon the new oscillator table;
- a filter coefficient data memory for storing sets of filter coefficients;
- means for interpolating between sets of filter coefficients stored in a filter coefficient memory based upon the input control signal to generate an intermediate filter coefficient set;
- means for interpolating within the intermediate filter coefficient set to generate a formant filter;
- and
- means for filtering the excitation signal with the formant filter to generate a tone.
An electronic musical tone generator for generating an electrical output signal representing a musical tone in response to an input control signal, comprising:
- means for generating an excitation signal;
- a filter coefficient data table memory for storing sets of filter coefficients;
- means for interpolating between sets of filter coefficients stored in the filter coefficient table memory based upon the input control signal to generate a formant filter;
- said means for interpolating including:
- a formant filter coefficient sequencer and interpolator for interpolating between the filter coefficient sets to form a variable rate decimated filter coefficient sequence;
- and
- a time varying formant filter generator for interpolating over time among the coefficients forming the decimated filter coefficient sequence to generate a series of filter coefficient sets for use in creating the time varying formant filter;
- and
- means for filtering the excitation signal with the formant filter to generate a tone.
An electronic musical tone generator for generating an electrical output signal representing a musical tone in response to an input control signal, comprising:
- a formant filter generator for generating a formant filter;
- an oscillator table memory for storing a plurality of oscillator tables;
- means for generating an excitation signal, including
- means for selecting and interpolating between at least two oscillator tables stored in the oscillator table memory, based upon the input control signal, to form a new oscillator table, and
- means for generating an excitation signal based upon the new oscillator table;
- means for providing the excitation signal to the formant filter at a desired data rate;
- and
- means for filtering the excitation signal with the formant filter to generate the tone signal.
Dependencies are inferred from the claim text.