Black Canary from DC: Canary's Cry?

It's my understanding that regardless of which Black Canary you're talking about (there were a few versions in print, now there are two in continuity though the original one is dead), you're still talking about an _inhumanly_ loud scream.

Something on the order of 200 to 400 decibels, easily. The miracle is that Black Canary herself doesn't go deaf from it. But to answer your question, it seems the main effects of the Cry at distance are pain and being deafened, and disoriented. So at a distance a deaf character might be ok--they might feel a bit of stinging vibration on their skin, that's it.

Up close though, it's another story. 200 decibels is enough to fracture concrete at close range, say within arm's length. In the "Tornado's Path" arc of the _Justice League_ comics (Metzler/Benes), the Black Canary tells her opponent that her cry "Can knock Gorilla Grodd on his [bleeped], so what do you think it can do to you from five inches away?" Or some such.

Point being....at point-blank ranges (arm's length or shorter) anyone not from Krypton is likely to have broken bones from the vibratory force of the screech, whether the noise is actually heard or not.

Hope this helps. Just FYI: it wasn't bleeped in the comics, but Yahoo!, you know how they roll.