I can do that. It is like a roar at the loudest point I can manage. A light effort sounds a lot like the ship thruster sound in Asteroids. I find I can clenc

I can do that. It is like a roar at the loudest point I can manage. A light effort sounds a lot like the ship thruster sound in Asteroids. I find I can clench the muscle, but can only and occasionally relax the thing. When I do clench, my ear response curve in the midrange, say 800Hz to a few KHz, is improved. Have a fan handy? Try it and listen. You may hear a lot more from that fan.