The Wanted felt ''something was missing'' without Nathan Sykes.

The 'All Time Low' hitmakers - which also include Siva Kaneswaran, Jay McGuiness, Max George and Tom Parker - were worried about their live sound when Nathan had to undergo surgery on his haemorrhaging vocal nodule in April and they had to share his lines between them.

Tom said: ''It's weird covering for anybody's vocals. It is weird. It is strange.''

Max added: ''We've all got good ranges in our voices and stuff, so we can always cover for each other.

''But for me, it was more when you watch it back and you'd hear a chorus, even if you stood onstage, you just felt like there was something missing.

''Whether it was his physical self or you could just, [hear it] in a chorus, you'd be like, 'It just doesn't sound as big as it should do.' ''

Tom admitted Nathan's absence also affected their routines, as they had been choreographed specifically for a five-piece band.

He said: ''We'd always leave a gap on set. And we'd watch it back, like, 'We left a gap there.' ''

Nathan, who made his comeback in London this June, was disappointed when he had to take time off work to allow his throat to recover.

During a Q&A session to promote their reality show 'The Wanted Life', Nathan added: ''You don't want to watch things because you're like, 'Oh, I'm not there.' But they did work their asses off.''