Abstract: Complex sound events are created by generating multiple different kinds of simpler sounds with randomly varying repetition rates. The average repetition rate can also be variable. The values of sound parameters such as wave selection, pitch distribution, pan distribution and amplitude distribution can have random distributions, as determined by various control inputs, some of which have their own random distributions.

Abstract: Computer-implemented techniques are provided for synthesizing sounds of an internal combustion engine vehicle using a physical model of the vehicle. In general terms, the method includes independently generating and/or synthesizing separate components of the vehicle sound, then combining these components to produce a final sound. Using a physical model of the vehicle, the separate components of the vehicle sound are independently generated from vehicle control parameters characterizing the operating conditions of the vehicle. The components are then combined using mixers and equalizers to produce a realistic vehicle sound. The present technique allows independent control of the separate components of the vehicle sound, is not limited to specific vehicles, and does not require recorded sounds taking large amounts of storage space.

Abstract: Computer-implemented techniques are provided for synthesizing sounds of an internal combustion engine vehicle using a physical model of the vehicle. In general terms, the method includes independently generating and/or synthesizing separate components of the vehicle sound, then combining these components to produce a final sound. Using a physical model of the vehicle, the separate components of the vehicle sound are independently generated from vehicle control parameters characterizing the operating conditions of the vehicle. The components are then combined using mixers and equalizers to produce a realistic vehicle sound. The present technique allows independent control of the separate components of the vehicle sound, is not limited to specific vehicles, and does not require recorded sounds taking large amounts of storage space.

Abstract: An efficient digital waveguide synthesizer is disclosed for simulating the tones produced by a non-linearly excited vibrational element coupled to a resonator, such as in a piano. In a preferred embodiment, the synthesizer creates an excitation pulse from a table containing the impulse response of a piano soundboard and enclosure. Alternatively, this excitation pulse can be synthesized by filtering white noise. The excitation pulse is fed into a filter that simulates the collision of the piano hammer and string. Because the hammer-string interaction is nonlinear, the characteristics of this filter vary with the amplitude of the tone produced. The filtered excitation pulse is then fed into a filtered delay line loop which models the vibration of a piano string. Because the excitation pulse already contains the effects of the resonator, the tone produced by the delay line loop does not require additional filtering in order to model the resonator.

Abstract: A coupled mode digital filter which simulates any number of arbitrarily tuned modes coupled together so as to share the same loss element at a junction loaded by an arbitrary impedance function is formed from the combination of one first order allpass filter ?28! and one unit delay ?30! per mode and one shared coupling filter?36!.

Abstract: A sampled data, non-integer delay line interpolation structure includes a sampled data delay line, two allpass filters, each having an associated read pointer for reading data at a corresponding integer position of the delay line, an alternating crossfader that alternatingly crossfades between the outputs of the two allpass filters, plus a controller that controls when the read position of each allpass filter is updated and also controls when the filter coefficient of each allpass filter is updated. A specified delay length value is sampled by the controller each time the crossfade orientation of the alternating crossfader is changed, and from that value the controller generates a new read pointer and filter coefficient for allpass filter to which the structure will next crossfade. The new read pointer is an integer that corresponds to an integer portion of the specified delay length, and the filter coefficient corresponds to a fractional portion of the specified delay length.

Abstract: A music synthesizer includes main resonator, such as a digital waveguide network, that is coupled to a digital passive nonlinear filter. The passive nonlinear filter receives traveling wave signals from the resonator and generates modified traveling wave signals having a different frequency spectrum than the received traveling wave signals without changing the received traveling wave signals' energy content. The passive nonlinear filter then transmits the modified traveling wave signals back into the resonator. The passive nonlinear filter includes a first memory element for retaining an internal energy state and a dual-mode signal generator that generates the modified traveling wave signal from the received signals and the internal energy state using a first signal processing method when the internal energy state has a negative value and using a second distinct signal processing method when the internal energy state has a positive value.

Abstract: A signal synthesizer uses a digital waveguide network having at least a three dimensional matrix of waveguide sections interconnected by junctions to filter one or more excitation signals so as to generate an array of synthesized output signals. The digital waveguide network has sets of waveguide sections interconnected by junctions. Each waveguide section includes two digital delay lines running parallel to each other for propagating signals in opposite directions and each junction has reflection and propagation coefficients assigned to it for controlling reflection and propagation of signals in the waveguide sections connected to that junction. Except for junctions along boundaries of the digital waveguide matrix, a majority of the junctions are 2.sup.w -way junctions, where W is an integer greater than 1.

Abstract: A signal synthesizer uses a digital waveguide network having at least a two dimensional matrix of waveguide sections interconnected by junctions to filter one or more excitation signals so as to generate an array of synthesized output signals. The digital waveguide network has sets of waveguide sections interconnected by junctions. Each waveguide section includes two digital delay lines running parallel to each other for propagating signals in opposite directions and each junction has reflection and propagation coefficients assigned to it for controlling reflection and propagation of signals in the waveguide sections connected to that junction. Except for junctions along boundaries of the digital waveguide matrix, each junction is at least a four-way junction that interconnect at least four waveguide sections so as to scatter and intermix signals in flowing through those waveguide sections.

Abstract: A musical sound synthesizer simulates interaction of a hammer having a compressible striking surface with a resonating medium. A digital waveguide resonator that simulates operation of a resonating medium and generates digital resonator waveforms representing signals propagating in said digital waveguide resonator. A hammer filter simulates the hammer striking the resonating medium and generates first and second hammer waveforms. The hammer filter includes a scattering junction that couples the hammer filter to the digital waveguide resonator.

Abstract: A microtonal key module includes a central key and a number of surrounding keys clustered about the central key. The central key and the surrounding keys establish among each other a progression of successive microtonal increments. A plurality of such microtonal key modules are arranged to form a microtonal keyboard system.