The Vais is a fine brake. It has longitudinal passages passing thru the ports, radially arranged around the bullet passage. These passages exit at the muzzle of the brake, in the form of neatly machined holes. Some blast and noise passes out of these holes, forward of the firearm as opposed to out the sides. The Vais is quieter than some other brakes because of this design, but it is not quite as efficient. However, it is louder than an unbraked rifle. But not as loud as the BOSS brake, which is real nasty. As to the degree of loudness, I don't own a decibel meter, so I can't really give you a quantitative answer. Another reputably quiet brake is the Gentry Brake. I am not personally familar with it, but have heard that the work is top rate. If you braked your rifle with one of these quiet brakes, you could wear those valve earplugs that shut upon firing, while out in the field. I think they only are rated for 7 or 10 db, but it is enough to break the peak on that sound wave before it reaches your ear. I'm talking while you are hunting of course, not shooting all day at the range.