If the things suggested above don't help you could try changing the firearm you are shooting.
You would be surprised how much less noise a longer barrel will make. And it's even better if you can figure out how to shoot a milder round, something that does not say magnum and that does not require a muzzle break to suppress the recoil.
Not a solution but fact is that a .308 with a long barrel is not near so hard on your ears as is a .338 Mag with a short barrel and a muzzel break.
Of course if you're having problems because of bird hunting with a shotgun......just getting to many shots.....then you need to invite a lot of friends so you don't have to shoot so much.