Good earmuffs will reduce loud noises by about 25dB, and only if they are properly fit and occluding the ears. When shouldering a rifle in awkward positions, it is common for the muffs to be bumped and lifted. Also, between a very loud braked rifle and then putting the #*&$ brake inside of a structure like the pictured concrete pipe, even with a 25dB reduction one is probably experiencing a loud enough sound to cause cochlear injury.

And I am anti-brake. They are obnoxious, especially if you’re next to the shooter using one on the line. If you cannot handle the brutal recoil of an 18# PRS rifle, use a suppressor with a brake!