Abstract: A vehicle engine sound simulator includes a crossfade sample playback engine which produces an output waveform comprising at least two constituent waveforms which are transposed up and down in frequency with RPM. The playback engine's output waveform is provided to at least one digital signal processing (DSP) circuit, which processes the output with a function that varies with the rate of change of RPM, an external load value, and/or a combination of both to produce the simulator's output. The crossfade sample playback engine is arranged to crossfade between at least 2 wave samples as RPM changes. Wave samples from additional wave banks associated with different load states can also be mixed into the playback engine's output waveform. The DSP circuit can include both nonlinear and linear processing sections in various combinations.

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.