Most notably known from The Film Theorists on YouTube, I, myself have not seen them, but I have been informed (from an unknown source) that mine and their theory are very alike. To start off, let me explain what "Decibels" are: what decibels are; are sound waves (sort of) that go through everything. around 65 decibels, your safe.... But when you go above 85 decibels, there is chance you can have permanent hearing loss. The gun Rick Grimes uses in the show "The Walking Dead" is a .357 Colt Python Magnum. Magnums have a tendency to have around 160 decibels in each shot, above the limit of which you can get hearing loss. Rick shoot this Magnum a little over 100 times on the span of the 5 seasons of the show. This is only with his Magnum, he also has a arsenal of other high-decibels weapon, the Shotgun for instance. They use an assortment of Shotguns in the show, but you gotta admit, that sh*t is loud as hell. If you; the watcher get a headache after watching this, then it would be possible for the Shotguns to do some real damage to the people who are holding it up right to their faces. Now, there is an exception to this: Daryl and Michonne. Their weapons of choice are silent, yet powerful. BUT, Daryl tends to run low on arrows, which are not that easy to come by, so he uses guns, like the rest. For instance, the Assault Rifle, and I don't know about you, but that thing shoot fast and it has probably over 100+ decibels, so Michonne has an advantage, being the only character in the show who has no hearing loss, can sense walkers behind her, and uses the most badass weapon ever: The Samurai Sword. Therefore every character possibly have hearing loss. That must be why they can never see a walker that is clearly right behind them, making a lot of noise, and for some odd reason, only Michonne can know when and where walkers are behind her.