In my experience Deer don't react to arrow noise in flight. I use feathers and there isn't any fletching that makes more noise than they do in flight, but in 40+ years Bowhunting I've yet to have a deer react to it

Birds are always flying around. They make a little noise too![8D]

I think that type of noise is more natural in the woods than the recoil sound of a Loud bow. Now Deer will react to that!

Dan