(simple) audio line-in triggered switch


I would like to build a project that allows sound - activated in the gaming engine Unity3D - to trigger a vibrating device. Anytime a character in the game walks into a marked region, a sound file would be played, and I the sound triggers a vibrating device in real time. I have seen a few descriptions of audio-triggered switches online and in the forums, but my impression is that these are more complicated than I actually require. I am very new to this and am hoping to find the simplest solution possible.

The particulars:

Unity3D is running on Linux The sound could be anything, such as a simple, non-variable single tone The vibrating device could be anything: a vibrating toothbrush, a small servo, whatever is easiest. Preferably something low frequency Vibration should overlap sound rather then just being triggered by it. As long as sound plays, the vibration should be on. The moment the sound ends, the vibration turns off

I am grateful for any suggestions or input!!

I don't know anything about your game (or any game, for that matter).

Does your sound file have to make an actual sound or could it just play a frequency to the Audio socket that is only for the purpose of triggering something?

As you are running on Linux is there an option to trigger a shell script rather than (or as well as) play a sound file?