Google for "convolution" and look at the convolve opcode in Csound. Usually, one convolves a short signal (the impulse) with a longer signal (the signal) to produce a result. Each sample of the signal is "multiplied" by the entire impulse. More precisely, convolution is the integral of the product of the two signals after one is reversed and shifted. Usually, this has the effect of "smearing out" the sound of the signal with the sound of the impulse, and this can resemble a blending or filtering of one sound with another. Using this effect is tricky and requires an understanding of what is happening. Convolution is a very basic concept in signal processing.

It is also possible to use more elaborate software tools such as Loris, which can "morph" one sound with another in a different way. However, I find that simple convolution is often preferable.

Regards,
Mike

-----Original Message-----
>From: Drweski nicolas 
>Sent: Feb 22, 2006 9:26 AM
>To: csound@lists.bath.ac.uk
>Subject: [Csnd] two sounds
>
>Hi,
>
>I was wondering if it was possible by any mean to pass
>a csound instrument through a wave/aiff/... files ; or
>the contrary. 
>For example, to pass a sine wave through a wind sound
>recorded in the nature.
>
>Nicolas Drweski
>
>
>	
>
>	
>		
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