An op gave Jackie her hearing back. So does that make her a traitor to the deaf?

Jackie Knight always remembered the Monkees.

Their Saturday night show almost 29 years ago was the last music she heard before a bout of meningitis caused her to become deaf when she was just five years old.

But now, at 34, she has had her hearing restored, thanks to a controversial operation which has divided the deaf community. Cochlear implants are being performed on record numbers of people but for many in the deaf world the surgery is a betrayal of deaf culture, and a threat to the survival of sign language.

It took Ms Knight a long time to agree to the operation but she eventually decided the benefits were too great to be dissuaded by opponents' arguments.

"It was the biggest chance of my life," she said. "I know there is a political situation about the operation and about its effects on the deaf community, but I wanted to be happy and to enjoy life. I don't think I should have to think about politics."

The operation has been such a success that it has given her confidence and a new career. Before her operation she was a road sweeper in north London; now she is studying for a law degree and plans to be a barrister.

There was a moment of poignancy when she regained her hearing: the first music she heard was by the Monkees, who are now on a revival tour.

"They were the last I heard and one of the first things I was able to listen to after the operation," Ms Knight said. "They played me 'Hey, Hey, We're the Monkees' in hospital and it reminded me of when I was a kid and watched their show on TV every Saturday night before I went deaf. I'm playing the music again, but it takes time to understand and I'm having to learn to hear over again."

New research has shown that adults who have lost their hearing, rather than those born deaf, and children aged up to seven benefit most from the implants because if the first years of life are soundless, the part of the brain that processes hearing may lose some of its ability to develop.

The main opposition to implants centres on the argument that deafness is not an illness to be cured. Critics see themselves as a linguistic minority group rather than people who are disabled and in need of help.

Dr Jim Kyle, Director of the Centre for Deaf Studies at Bristol University, once said when asked to explain this opposition: "Cochlear implant programmes epitomise the medical response, or medical model approach, to disability. It starts from a premise that deaf people are ill. Deaf people challenge this. They don't see themselves as suffering from an illness or disease. They don't need to be cured."

Ms Knight's operation was filmed in detail for the first time by a BBC camera crew for a documentary, See Hear, to be shown on BBC1 tonight. The film's editor, Bryn Brooks, said: "We can understand what it is to be blind because we shut our eyes and we walk into the furniture.

"Deafness is very different, it is all about communication. For deaf people it is bliss to meet up with other deaf people and they will travel hundreds of miles to communicate with each other.

"The idea that doctors are going to do something which is going to reduce the number of people in the community gives the message that life for the others is going to be worse."

In a normal ear, sound-waves make the eardrum and tiny bones vibrate, sending vibrations through the fluid of the inner ear, or cochlea, where thousands of minute hair cells convert them into electrical impulses. These impulses stimulate the hearing nerve to send signals to the brain, where they are perceived as sound. In someone who is deaf, the delicate hair cells have usually been damaged or destroyed, cutting off the supply of data to the brain.

During a cochlear implant operation, electrodes are implanted deep inside the ear. Messages can be sent via nerve fibres to the brain and the sensation of sound can be recreated. A special hearing aid is worn.

Lord Ashley, the former MP Jack Ashley, was one of the first deaf people to have an implant. He describes being able to hear as an "absolute miracle".

He is now trying to persuade all health authorities to offer the operation and rejects criticism of it.

"An hour ago I was listening to the birds in the garden," he said. "That really is a miracle because I was totally deaf, not just profoundly deaf.

"I respect the views of the deaf community. If people don't want cochlear implants they are entitled to their views as individuals but ... all kinds of wild allegations are made.

"My view is very strongly that everyone who wants an implant and can benefit from it should have one one.''