Music synthesizer system and method for simulating response of resonant digital waveguide struck by felt covered hammer

A musical sound synthesizer that simulates interaction of a hammer having a compressible striking surface with a resonating medium, comprising:

• a digital waveguide resonator that simulates operation of said resonating medium and generates first digital resonator waveforms representing acoustic frequency signals propagating in said digital waveguide resonator;
• a hammer filter coupled to said digital waveguide resonator by a scattering junction for simulating said hammer striking said resonating medium and for generating a first hammer filter waveform;
• said scattering junction including a first port for receiving said first digital resonator waveforms generated by said digital waveguide resonator;
• a second port for receiving said first hammer filter waveform;
• a third port for transmitting into said hammer filter a second hammer filter waveform, wherein said scattering junction generates said second hammer filter waveform by combining a first time varying portion of said first digital resonator waveforms received from said digital waveguide resonator with a first time varying portion of said first hammer filter waveform;
• and a fourth port for transmitting waveforms into said digital waveguide resonator waveforms, wherein said scattering junction generates said transmitted waveforms by combining a second time varying portion of said first digital resonator waveforms received from said digital waveguide resonator with a second time varying portion of said first hammer filter waveform;
• said hammer filter including
• a compression function that generates from said first and second hammer waveforms a compression value corresponding to compression of said simulated hammer;
• a stiffness function that generates a time varying stiffness coefficient as a function of said compression value;
• and
• a excitation signal function that generates a hammer excitation signal as a function of hammer strike impulses;
• a hammer function that generates said first hammer filter waveform as a function of said compression value, said hammer excitation signal and said second hammer waveform;
• wherein said scattering junction passes said first digital resonator waveforms received from said digital waveguide resonator unchanged to said fourth port when said compression value corresponds to said hammer not being compressed and otherwise transmits through said fourth port said second time varying portion of said first digital resonator waveforms received from said digital waveguide combined with said second time varying portion of said first hammer filter waveform, wherein said second time varying portions of said first digital waveguide waveforms and of said first hammer filter waveform are functions of said compression value.

A method of synthesizing sounds associated with interaction of a hammer having a compressible striking surface with a resonating medium, comprising:

• providing a digital waveguide resonator that simulates operation of said resonating medium and generates digital resonator waveforms representing signals propagating in said digital waveguide resonator;
• and
• simulating said hammer striking said resonating medium by generating first and second hammer waveforms, including:
• generating from said first and second hammer waveforms a compression value corresponding to compression of said simulated hammer;
• generating a time varying stiffness coefficient as a function of said compression value;
• generating a hammer excitation signal as a function of hammer strike impulses;
• and
• generating said first hammer waveform as a function of said compression value, said hammer excitation signal and said second hammer waveform;
• transmitting said digital resonator waveforms received from said digital waveguide resonator, unchanged by said first hammer waveform, back into said digital waveguide resonator when said compression value corresponds to said hammer not being compressed, and otherwise transmitting into said digital waveguide resonator a first time varying portion of said first digital resonator waveform combined with a second time varying portion of said digital resonator waveforms, wherein said first and second time varying portions of said first digital waveguide waveform and said digital resonator waveforms, respectively, are functions of said compression value.