The world became a whole lot louder for an 11-year old this week, thanks to her campaigning mum and a "miracle" operation.

Anabelle Sonmez was born profoundly deaf. For three years, mum Samantha Sonmez has been battling bureaucracy to get her the bilateral cochlear implant that would allow her to hear in both ears.

The legal secretary had all but given up hope after Surrey Primary Care Trust turned her down. But a change in the guidelines saw Anabelle going under the surgeon's knife for a three-hour operation at Christmas.

And as her doting mum looked on, the implant was switched on for the first time on Monday at the audiology department of St George's Hospital, Tooting, causing Anabelle to jump a foot in the air off her chair, before breaking into a cautious smile.

She told the Mirror: "It is going to take me some time to get used to. They turned it on and it was just noise at first.

"But I am really looking forward to going to my hip-hop dance classes and listening to the music, and I want to hear my dog Charlie barking. It's not all good. I guess it's going to be harder to ignore my mum nagging."

Mum Samantha, of Sunnybank, Warlingham, admitted to feeling a little overwhelmed after watching the implant being switched on for the first time.

She told The Mirror: "It's been a tremendous day. It's just amazing how something so small as the implant can have such a profound effect on someone's quality of life.

"I have been so worried about Anabelle just doing normal everyday things like crossing the road. And I hope she will be able to go on to university, but worried her hearing problems might hold her back.

"She has one, old, implant in her right ear. But this is going to open up a whole new world to her. For the first time in her life, she will be able to tell where sound comes from, and to hear it properly."

The implant works by using a microphone attached to the outside of the ear which transmits a signal through the wearer's head to a receiver surgically implanted into the ear.

Audiologist Eleanor McKendrick, who calibrated the implant by playing Anabelle a variety of tones and volumes, was delighted by her response.

She said: "It's difficult, at first. The brain has to learn how to interpret the new signals it is getting, and that takes time.

"For a while, it is normal for speech to sound like the ringing of bells. The world can seem like a noisy place the first time an implant is switched on. But usually after a matter of weeks things become a lot clearer."