Louise and Callum Sherlock and family A mother who went deaf when her baby was just three months old is beaming with joy after hearing his voice for the first time.

Louise Sherlock, 24, from Oxford, lost most of her hearing after suffering meningitis as a baby.

Then last year, she was devastated when she lost the rest of her hearing before her son Callum could utter his first words.

Four weeks ago, in a bid to hear again, she underwent a delicate, two-and-a-half-hour cochlear implant at the Radcliffe Infirmary.

And yesterday surgeons turned on the equipment and she heard her son speak.

"I can't stop smiling," she said.

"For the past four weeks I have been so anxious waiting to see whether the operation had worked.

"When we got to the hospital the hearing specialist hooked up wires to my new hearing aid and started playing high frequency sounds.

"All of a sudden I started to hear loud, high pitched sounds. Then I heard her voice and it wasn't robotic at all, like I'd been told to expect. She sounded normal and I knew the operation had worked."

Louise's family, friends and Callum, aged one, had been in an adjoining room while the tests were carried out.

Her mum, Gail Sherlock, 45, said she cried as she saw Louise's face react to the sounds.

"I was watching her so intently, then I saw her smile and I knew," she said. "Straight away we took Callum to her and told him to say 'mummy', but his favourite word at the moment is 'No' and when he shouted it out, Louise laughed."

"Callum's voice is low and baby-like. It's lovely," said Louise.

"My mum's voice, which I have tried to remember for as long as possible, still sounds exactly the same.

"And when my nan shouted 'hello' from the other room. I heard her straight away.

"I don't think it has really hit me yet, but I can finally hear again."

Cochlear implant surgery has only been performed on 60,000 people worldwide, and is usually only funded for children in Oxfordshire.

But doctors made an exception because Louise cares for Callum on her own.

During surgery an electronic cochlea was implanted in her inner ear. This bypasses the damaged part of her ear and and directly stimulates the hearing nerve.

Sounds are then relayed by a small device worn on the outside of the ear, which is held in place with a magnet.

"Now I can't wait until Friday when I'll be going back to the hospital for more tests and tuning," she said.

"Over the next few months, I'll have to get used to lots of new sounds.

"But I know I can achieve this and learn to hear well again.

"What I'm most looking forward to is getting home tonight, putting on my new CD player and having a good dance to some music with Callum.

"Hearing him sing The Hokey Cokey at last will be just fantastic."

Radliffe Infirmary consultant audiologist and coordinator of the Oxford Cochlear Implant Programme Jane Jones said: "We are delighted, but there is a long way to go after this very optimistic start.

"Louise has a lot ofwork before she is optimally tuned in, but we are very happy it has all gone so well."