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.