It's been four years since the Killers released their last album, 2008's 'Day and Age.' The Las Vegas foursome took a year-long hiatus in 2010 and reconvened last year. Since then, the band has been working on its new album, 'Battle Born,' and frontman Brandon Flowers recently revealed he even took singing lessons to help prepare himself to record the new disc.

In an interview with Rolling Stone, Flowers considered the Killers' brief break as training for 'Battle Born.' The group members focused on various side projects while their main band was put in the back burner. However, none of them let their focus on Killers material slip from their minds. "It was like being in training," says Flowers. "I was keeping myself not just occupied, but ready."

The dance-rock veterans brought in multiple top-notch producers to work on 'Battle Born' with them, including including Brendan O'Brien, Steve Lillywhite, Daniel Lanois, Björk associate Damian Taylor and dance-music maven Stuart Price. The group waited until they knew the exact direction they wanted to take with 'Battle Born' before reaching out to producers. "It's a little bit our fault," Flowers admitted. "We thought we would wait to see what the album was before we pulled the trigger on who we wanted." Added drummer Ronnie Vannucci, "We're not used to splitting up our brains like that."

Despite the different collaborators on 'Born Battle,' fans can be rest assured that the album will keep the Killers' trademark sound intact. "We write a very particular type of song when we get together," Flowers stated. "So many people try to find something wrong with it, but I'm not embarrassed by it."

Tragedy struck the Killers in April when saxophonist Tommy Marth committed suicide. The musician played on the band's previous two albums and joined them on the road. They considered having Marth featured on 'Battle Born' before his unexpected death. "He was a crazy motherf----r, but in a great way," Vannucci said. "He would joke about serious stuff, but always throw it into the comic realm. Nobody ever said, 'Tom, you OK, dude?' We wrote a new song a couple of weeks ago, and we were thinking about having him come in to play on that, but it never happened."

The Killers are still putting the finishing touches on 'Battle Born,' but they want to have it out by fall 2012. While they hope to stay on schedule, growing older has certainly affected their recording sessions. "It gets harder as you get older," Flowers, who turns 31 this month, admitted. "You want to put in the same effort, and find the same focus you had when you knew you didn't want to work at the casino anymore. We're working it out."

Watch the new trailer for 'Battle Born' here.