Question on sound files

I am in the process of hooking up a bass shaker under the ejection seat of my cockpit. It takes the sound files from the simulator and converts them into low frequency vibrations that simulate aircraft vibrations.One of my pet peeves is the lack of noise or vibration when the speed brakes are deployed on an aircraft. So, i have been looking at the sound SKD and sound cfg files of various aircraft.The SKD doesn't specify a specific sound for the speed brake. However, I see in some aircraft sounds that are not listed in the SKD i.e., Tailhook, launchbar, etc.If I use a rumbling sound and rename it [speedbrake], how do I get FSX to activate it when I extend the speed brake? I see no references to activations for the sounds.