Billie Eilish is going through a "different" creative process for her next album.

The 'Bad Guy' hitmaker is working on her third record with her brother and collaborator Finneas and explained how she has experienced a "big jump" between the ages of 18 and 21 since the release of her debut 'When We All Fall Asleep, Where Do We Go?'.

Speaking on Dua Lipa's 'At Your Service' podcast, Billie said of the music making process: "Everything is different about it. I've been trying to compare recently, just because I'm getting used to doing it in a different way. And trying to be like, 'It's OK to do that. I'm OK. I'm still able to do that; I'm capable still.'"

The star discussed the transition from making music in her childhood home to working in Finneas' basement studio for her last album 'Happier Than Ever' and felt as if the pair had "figured out" the process.

Billie explained: "We were like, 'We've got it all figured out, this is how we're going to do it from now on, and it works really well.'

"And, you know, touring for a year-and-a-half, then coming back to it, and being way older - and not even much older, but again, the jump between 18 and 21 is a big jump."

Billie revealed that she is trying to convince herself that she hasn't "lost it" as her vocals have changed.

She said: "The way that I exist in the room is different, my voice has completely changed since then... The voice-changing thing is a trip! It's all kind of shocking.

"I've gotten a little bit more like, 'OK, it's just change and I'm figuring that out.' It's hard to accept change, it's hard to get over, 'But I did this way for so long, and it worked so well!' Well, you can't anymore."