I agree that the heavier arrows reduce the "noise" a deer hears buttttttt.
I did some very unscientific testing, whereby i stood very close to the target, 5yds away, behind a barrier off to the side and listened to the arrows as they came to the target.
You would be very surprised the amount of "noise" an arrow makes !!!
Ultimately the less feathers or vanes you have, (length, height, or the number of) the less "noise" the deer will hear.
I used to shoot 5" high shield, I am down to 3" low shield and still hear a little bit of "noise" but considerably less.
Make very sure your arrows are bear shaft tuned well, so you need minimal feathers.
After watching slow motion videos of the arrow traveling to the deer, it seemed to me they seemed to be reacting to the arrow.
YMMV.