What type of audio module are you using? If you're using one of those audio modules from Radio Shack ($10), I know they are very sensitive to voltage spikes and feedback...I have a great deal of experience with the puppetmasters, and if you're using a pneumatic solenoid valve or relays in your applications, you definitely need to put a diode across the voltage pins leading to the valve or relay (unless it's 120V!!!)...I'm only talking about low voltage relays or valves (12-24 v dc)....your audio module is picking up voltage fluctuations in your power supplies, which is why you should only use regulated adapters. You can also try to put a capacitor across the trigger of your audio unit to absorb any spikes which could falsy trigger your audio....selecting the correct cap requires a little electronics know-how, though...
If your audio is falsely tripped when the puppetmaster is activated, keep in mind that the puppetmasters have an internal relay which DO NOT have diodes acoss the pins for spike supression, so sometimes the relay will generate a small spike which the audio module will then interpret as a "trigger" especially if they are plugged into the same power source....if you can give me some more details, I may be able to offer a viable solution....
Sorry for rambling....