8 yr old dd - talking in baby voice driving me mad - any advice?

[ilovecake]

DD seems to spend 80% of her time talking to me and my husband in a babyish lisping voice - been going on for at least year but seems to be getting worse. She doesn't have problems with her speech and i have asked her teacher who seemed amazed as she said she is so mature in school. I've really tried ignoring it and/or saying "please talk to me in a clear voice" but its not reducing! Now when she enters the room i am on edge with frustration because i know she is going to do it and so i am tense around her - it is really affecting how i feel about her. Does anyone else have this with their child or have any advice?

I actually remember doing this as a child!!

My Mum used to say 'Speak properly and stop talking like a baby!' or 'stop using your baby voise!' I used to stop instantly, I remember feeling embarrassed that I was doing it! I think it was a habit I picked up from school friends or something, cos I certainly didn't think one day 'I'm going to talk like a baby now'!! It just happened.

Weird.