I’ve switched to non-vented heads to reduce noise. That said my bow still makes noise. My string still makes noise. My fletchings still make noise. Everything I shoot still hears the shot before my arrow arrives and sometimes they react while other times they don’t...I chalk that up to the animal’s individual personality, state of arousal/alertness, and how much experience they have with hunters more so than my equipment. However we can all agree that more quiet equipment is objectively speaking better for hunting and because of this simple truth I have paid very close attention to noise as I tune my rig and arrows. I feel more confident having switched to quieter built arrows. I don’t know if it has truly resulted in more game being harvested or not for me but it has improved my confidence and therefore my satisfaction when it all comes together perfectly and I know it’s because I’ve combined well tuned/built gear, with woodsmanship, with experience, and with luck to put food on the table. I say if you are doubting your heads even a little bit, switch to another head that gives you absolute confidence.