[Openal] How to vary the speed of sound

[Chris Robinson]

On Monday 19 May 2008 01:11:02 am you wrote:
> I have not much understood what you told me.
>
> Does the change of the speed of sound of a playing source  is possible or
> not with OpenAl? If so how please?

It is. The playback speed of a sound can be changed using the AL_PITCH and 
AL_VELOCITY source properties, as well as the AL_VELOCITY listener property. 
For example, this will make a source play at half speed:

alSourcef(source, AL_PITCH, 0.5f);

> I'm starting using OpenAl and I know very little about it. Then, if you can
> help me with bits of codes that would be a pleasure.

It's not a problem to help. :)