Los Angeles, Dec 22 : Hollywood actress Nicole Kidman plays the award-winning American star Lucille Ball in the new biographical drama film 'Being The Ricardos'. Kidman has revealed that she turned to smoking in order to perfect her "deep voice", reports femalefirst.co.uk. She shared: "They decided Lucy needed to have a deep smoker's voice, so I started smoking. If I warm up for a minute, I now can do her voice standing on my head." Nicole also discussed how her age has impacted her career opportunities. The actress, who is married to musician Keith Urban, told DuJour magazine: "There's a consensus in the industry that as a female actor, at about 40, you're done." "I never sat in a chair and heard someone say, 'You're past your due date,' but I've had times where you're turned down and the door is shut on you." Kidman made the comments shortly after conceding that she hasn't got the voice to star in a Broadway musical. The Oscar-winning actress is one of the most sought-after talents in Hollywood, but Kidman would feel "insecure" singing on Broadway. Asked about the possibility, she replied: "I don't think my voice is strong enough. It's not strong enough. I mean, Broadway is like ... and also I just would feel so insecure." Kidman is a huge fan of Broadway musicals -- but she doesn't feel ready to perform in one. She said: "I want to go and watch Broadway. I love going to see Broadway. I can't wait to see Hugh Jackman. 'The Music Man', here we come! But yeah, no. I don't feel strong enough or secure enough to sing on Broadway." /IANS