Clifford is not the only Austalian band's member whose hearing got damaged because of the screaming fans, reported Ace Showbiz.
"I went to a hearing check-up, and I've actually lost high-pitched... Noises in my right ear. I think they've lowered or something," Clifford said.
"That's the effect (fans' screaming) has," Clifford's bandmate, drummer Ashton Irwin, added.
5 Seconds of Summer is currently serving as a supporting act at the shows on One Direction's tour which is scheduled to be wrapped up earlier next month.