It's impossible to tell if a person is deaf just by looking at him/her, but if they put a sticker or make tattoo of a mute speaker it can make life much easier.
After someone posted the picture on Facebook people are fighting over the tattoo and some even don't agree with the mute speaker symbol.
Let's see what this guy wants to say.
What's the solution?
Well, even though he is right but I think sometimes people don't take the meaning literally. So we have to consider how normal people think about this too.
Let me give an example. Imagine someone watching TV and for some reason he does not want to listen to the sound, so he presses the mute button, because he knows that when ever someone presses the mute button he can't hear the sound from that device.
For this reason most people think that mute means you can't hear and nowadays electronic devices made us think like that way too. So now if you put a mute sign next to your ear, most people will think you can't hear with that ear.