The individual that I referred to , had no issues at all with his hearing until after the brake was installed. The increase in noise due to the brake, was enough to cause him permanent hearing damage after taking a single shot without hearing protection while hunting with the brake installed.
Brakes do not increase the noise that comes out of the muzzle, they redirect the direction of it.
Anyone who shoots a loud centerfire should be wearing hearing protection regardless of a brake or no brake.