This photo shows how to build a Bouncefree circuit. This device prevents multiple exposures from secondary noise when capturing images with a sound trigger. It locks out audio signals for 3 seconds after the initial soundwave triggers the flash. This device is used between the flash and the sound trigger/mic. This circuit does not work by connecting directly to a microphone. Every thing you need for this circuit should be available at a Radio Shack store. If you understand how a breadboard works, adding a power switch and soldering to a printed circuit board (PCB) should be easy. Mount the device in a project box (available also at RS) and you have a new tool to use for your HSP. (Not resonsible for damage to your equipment. Use this info at your own risk.)
The polarity of the mini-jack determines which lead is wired to pin 3. It looks like I used a stereo jack instead of a mono jack for this circuit. You may be surprised to find that some stereo jacks have a different polarity than mono jacks so I always test the polarity of the jack. Keep in mind that the tip of the plug is (+). Use a multimeter as an ohmmeter to determine which lead of the mono jack will connect to the tip of the plug. The other lead is the (-). If you use a stereo jack, test all the leads to ensure proper connections.
Schematic for this circuit: