A-833 Rapping

What I don't get is that the tempo does not change. I would think the knock or rap would speed up or slow down with the rev of the engine or speed of the car, it does not. It only gets louder when I step on the throttle. Everything in the tranny should spin at different rates and at a higher speeds than the rap I hear. The input shaft should spin with the flywheel which is much faster than the rap which is every second or two. Is there anything in the tranny which spins at a constant speed regardless of the rpm and the gear your in. Would first gear spin faster than 3rd etc. Even the output shaft should be relative to the rpm I would think.

Steve