Some brakes are worse than others. I was shooting the AAC 51 tooth mount/brake in 3 gun since it worked with my can. Doubling up on ear pro worked fine for my ears, but the overpressure would often blurr my vision, I guess because it was messing with my retinas. I switched to a Lantac dragon for 3 gun and it is much better for the shooter.
Shooting a brake, plugs under muffs seems mandatory. My ears will ring if the plugs aren't in. Electronic muffs on top of plugs are great, you can crank up the volume to a comfortable level to where you can hear conversation and range commands, and you're still double protected.