When you've consumed copious amounts of alcohol and the more you drink the louder you talk & the louder the music gets.
Drunk1: It's too loud
Drunk2: (yells) What!!
Drunk1: Ah mate your Bloody drunk deaf
Deaf drunk is when an intoxicated person talks louder than normal because he or she thinks people can't hear him/her.
Wow, that drunk guy is talking so loud, he's deaf drunk.