In a quiet woods setting (hunting deer and hogs), sound travels.
Sound travels at 1088 Ft./Sec. therefore, an arrow traveling at 200 FPS will arrive at a spot 15 yds. away roughly 5 times slower than the sound of the shot. Regardless of how quiet your bow is, a deer/hog has ample time to react to the shot, thus dropping their body to load their legs, in order to run. My theory is to focus at the lower part of the Brisket, which allows the animal to drop into the arrow's path. It has worked for me and I hope it helps you as well.