I have found plugs and muffs to be quite effective when using a brake, although I don't know for sure whether they are "sufficient."

I understand, however, that electronic, active noise earmuffs that operate on the principles of waveform superposition and destructive interference are sufficient to protect a shooter against hearing damage when using or around another person who is using a braked rifle.

These muffs use microphones (the better ones use two microphones, one for each earmuff) to detect the noise of the shot, then cycle it through an electronic circuit that produces an effectively instantaneous acoustic signal equal in amplitude to that noise, but 180° out of phase with it. This completely cancels its energy and effect.

These earmuffs also permit normal speech and other sounds to pass through to the ear unimpeded. However, there is no way I could or would hunt while wearing such uncomfortable and bulky headgear.

Muzzle blast is another story. No hearing protection will have any effect whatsoever on the muzzle blast from a braked rifle, which can feel like a physical blow in some calibers and with some brakes. Muzzle blast is what most people wearing hearing protection object to when they experience a shot from a braked rifle, whether they realize it or not.

And both the increased noise and the increased blast from a braked rifle generally affect by-standers far more than they do the shooter. These "third party" effects result from the way a brake redirects the gases escaping from the rifle's muzzle.

As for using brakes in the field, I say absolutely not. If the shooter does not wear hearing protection, and most don't wear any protection while hunting, a braked rifle will seriously damage the shooter's hearing.

And, IMHO, using a braked rifle in the field is very nearly criminally inconsiderate to others around the shooter, such as a PH and trackers. Without hearing protection--and needless to say, they NEVER wear any--even one shot from a braked rifle can result in significant permanent damage to their hearing, much more damage than would result from firing an unbraked rifle.