In my experience, things that will reduce noise --
1. Getting the bow in perfect tune! Cam(s) synchronized and yoke tuned. Arrow rest at or very close to centershot. When the bow is pushing the arrow perfectly straight in a synchronized motion, more energy is imparted into the arrow and less into making vibration.
2. Losing the peep sight tube. Learn how to tie them in straight without the tube. The peep sight tube makes one heck of a thwack when you shoot.
3. Using heavier arrows. Heavier arrows will quiet a bow down substantially. Drawback is that you lose speed, but you do pick up momentum.
4. Using a good stabilizer with shock absorbing thingies, Limbsavers, and string leeches, etc.
5. Making sure everything is tight and eliminate any rattles discovered by the smack test.
6. Finding a quiet mechanical release. Some mechanical releases crack like a mother. I use a Scott single caliper (Wildcat) and it's fairly quiet. Noticeably quieter than my dual caliper TrueBall and Tru-Fire.