Helena Bonham Carter believes playing classical music to her children made them ''unbelievably clever''.

The 'Cinderella' star - who has son Billy, 11 and seven-year-old daughter Nell with her former partner Tim Burton - believes exposing her kids to the likes of Mozart whilst she was pregnant with them has made them more ''alert''.

Speaking to Classic FM, she said: ''I basically played Mozart and violin concertos again and again because it stimulated the inner ear of the unborn baby.

''And everything that they promised happened to both my children. They came out alert, unbelievably clever, and very relaxed.''

The 48-year-old actress previously admitted she worries about doing ''badly'' at parenting and struggles to balance her work and home life.

She said: ''Juggling motherhood with acting is hard and I'm always dropping balls all the time. You always feel you're doing everything badly...

''The multi-tasking is tiring. I'm not saying it's a big deal, not if you enjoy your work, and I'm lucky enough to make a living from something I love, but there's always something.''

Despite worrying about ''juggling'' her job and her kids, the 'Alice in Wonderland' star has admitted she never wants her career to finish and hates when she gets a lifetime achievement award as she thinks it signals the end.

She said: ''I just hope I carry on getting [great roles]. The only thing about getting this kind of award is it's a lifetime achievement award, and maybe it's a hint to stop. I just want another good job.''