The mum-of-two 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."
Helena, 48, who shares two children – seven-year-old Nell and 11-year-old Billy Ray - with her ex-partner Tim Burton, revealed her passion for classical music to Charlotte Green for the weekly Culture Club.
She said: "I love classical music.
"In fact I often listen to Classic FM. It's the soundtrack to my daily life because I find it really genuinely de-stresses, and I feel it can be a genuine healthy drug."
Finnish researchers discovered in 2013 that babies could remember music they were played in the womb for up to four months.
However, it did warn that those played classical music in the womb may not turn out cleverer than average.
Linda Geddes, author of pregnancy book Bumpology, said at the time of the study: "There is still no good evidence that playing music to your bump will boost your baby's brain development.
"However, research suggests that unborn babies can learn to associate their mother relaxing with a particular song."