whaddya expect? AC/DC only plays about 7 or 8 different songs from his perspective. Oh sure, they have a catalog with 100's of recorded songs on albums. But if you break them down, there's only about 7 or 8 actual songs from his point of view. Rinsed and repeated six ways from Sunday. The poor drummer is probably bored to tears or deafened by the lead guitar amps years ago.
I don't know how any of them still have their hearing. After each concert, even with protection, I know my hearing was seriously addled for a couple of days.