Competition don't need a quieter bow. Hunting however is nice to have stealth on your side.

String..... could put some cat whiskers on. Cheap and effective. I buy packs and split sheet into 1/3 then trifold that and tie on. Then cut looped ends and fluff up.

String stopper. Might loose a few decibles but with mine the bow shot so much smoother. Might gain a few FPS also.

Heavier arrow will help with noise. Maybe something around 400gr plus.

S-coil stabilizer can help

Limb saver or bowjax pads for limbs and cable guard