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

[Steve B. <sjb...@ai...>]

Christos Dimitrakakis wrote:
>> 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.

And of course there are things in cars that cut in and out depending
on speed, RPM and engine load.  A turbocharger for example has a distinctive
sound but only starts spinning when the engine is producing a certain
amount of exhaust gasses.  At low RPM, it's totally silent - at higher RPM,
it kicks in and changes the engine sound as well as adding it's own sound.

---------------------------- Steve Baker -------------------------
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