There are hundreds of different "digital potentiometer" chips available to do this.
Accuracy is typically specified in parts/million. Â
You can use them directly on analog audio or use them to set gain of amplifier stage.
Communication software for this is trivial if you can flip a few bits on a computer port.
On Nov 17, 2011, at 3:40 PM, PaweÅ KuÅmierek wrote: