The Brooklyn star has been gracing the New York stage opposite Skyfall actor Ben Whishaw since previews began on 1 March (16), and she reveals her vocals have taken hit due to their hectic schedule.

"My voice is gone," the 22-year-old told U.S. breakfast show Good Morning America, before comparing it to one particularly gravelly-voiced musician.

"I sound like Tom Waits right now! I basically sound like Tom Waits all the time onstage!" the Oscar nominee laughed.

Saoirse went on to compare the differences between working onstage to acting on a film set, admitting theatre work is much more physically demanding.

"Everything is so minimal, or it should be, I think, when you've got a camera right there (on a movie set)," she said. "It is different with theatre, it does need to be more physical and because of that, the stamina that you need to keep that up every single day, six days a week is much greater."

The Crucible, a new production of Arthur Miller's acclaimed 1953 drama about the Salem Witch Trials, is due to run until 17 July (16), and Bronx-born Saoirse is enjoying exploring the city of her birth after her family relocated to Ireland when she was three.

"It's the best, I love it so much," the actress gushed about life in the Big Apple. "For a while I thought, 'Oh God, I've always sort of romanticised New York. I wonder will it live up to the expectations?', and to come back here and just be able to like, wonder around the Village and stuff is just wonderful. I'm just really in love with the city."