Sound Source as a trigger

[RoyalHaunt]

Hello,
This is my first year creating a pneumatic prop and I needed a controller so I purchased the Prop 1 and must admit it has been great. Being a newbie and all I do have a quick question in regards to something I would like to do, I would like to use a sound source as a trigger for my program. Is this possible? I would imagine that I would need to convert a sound source to an electrical current. If that is the case, does anybody have any suggestions out there on the best way to do so.
Thanks

[JonnyMac]

It could be as simple as an open collector opto-isolator.  If you'll give more details I'll whip up a suggestion circuit.

[RoyalHaunt]

Thanks, I appreciate it.