Here's my problem. I'm a quadriplegic confined to a power wheelchair, & I control it using a sip & puff system. When I activate the chair, the drive mode latches in the on mode and to stop, I give it the opposite command. The tube that I use to suck or blow air into sometimes will fall out of my mouth and the wheelchair will continue to go until I hit something that stops me. I have broken my left leg twice. I have no control to stop the wheelchair. There is a manual switch that most people can use to stop, but it does not work for me. So, the solution, I believe, would be a voice activated momentary switch with a microphone on my control tube where I could yell something to close the switch then have it open so I could continue when someone gives me the tube again. I'm looking at a sound activated switch but do not think it will work because when I'm in a noises area the chair would keep stopping?? Any ideas?