Well...yes and no. Differences, if any, depend on a lot of variables. Some bows will show a performance difference, some won't.
I think most of the difference in noise is pitch rather than volume, but that's just my opinion--I haven't used equipment to measure it, and I haven't tried nearly every bow out there. I've hunted with absolutely whisper quiet selfbows, but the deer can still hear the shot......and I know of guys killing deer with bows that sounded like a car door slamming at the shot. Go figure.
I've only been tinkering with strings for 20 years or so, and I've never experienced a big difference in performance even when switching from a moderate dacron string to a "skinny" FF string...but that's just me.
Chad