User blog comment:Xilinoc/Ch. 561 - THE VILLAN/@comment-1268838-20131212223816/@comment-1268838-20131213051318

Any kind of damage to your eardrum can impair your hearing, even a pinprick. This guy shoved his index fingers into his middle ear; that isn't even possible without an obscene amount of force. A perforation of that size - which could very well be the entire surface of the membrane - would in fact result in major conductive hearing loss. No, maybe not total deafness, but temporary hearing loss is hardly outlandish. It's documented. Would that be enough? Kubo says yes.

We can delve into semantics and speculate on how loud Rose's music is. It's presumably orchestral, and clearly not death metal-loud - that might make him go deaf on its own. If voices become mumbles, then what does beautiful music become? If its illusions work by invoking feelings and emotions, would it even work if you can't hear properly? Heck, did Rose even get to execute his last move, or did the extremity of Mask's possibly misguided tactic distract him before he could?

Frankly, the fact that I have to crack open the medical dictionary just to make this argument shows how ridiculous it is to nitpick on this issue. Even if it were true that Mask should have his hearing, I find it difficult to imagine that it's really that hard to suspend your disbelief. Of all the things Kubo has done, "no eardrums = deafness" is the least scientifically offensive thing he has done. If anything, in the category of Anatomy & Physiology, that achievement goes to fact that the innards of all the characters in the series are apparently made of red Jello.