Re: [Plib-devel] OT: engine sound synthesis

[Christos D. <dim...@id...>]

> Isn't there a method that can change playback rates of soundclips without
> changing the frequencies on the sound?

It is called time-stretching and it will not work well for this sort 
of thing. The method you used, resampling is better:

Engine sound is made up of two things:

1) The stimulus, which is created by the firing of the 
engine, and which it's correct to actually 'resample', by skipping or 
averaging samples

2) The response, which is basically how the engine compartment and 
exhaust respond to the raw engine sound. You can describe that as 
some kind of IIR filter, maybe.

So, the best thing to do is to record the engine from very close, then 
somehow derive the filter description of the whole car, perhaps with 
the exhaust as a separate model. Then resample the engine sample to 
the appropriate frequency and pass it through the model. The result is 
an engine sound.

-- 
Christos Dimitrakakis
IDIAP (http://www.idiap.ch/~dimitrak/main.html)