By Julian Sturdy
A new treatment for stammering developed in the US involves fitting patients with an earpiece echoing their own voice.
Twenty-five-year-old Heidi King is one of the first British patients to try it.
Heidi is the life and soul of any party. Intelligent and vivacious, she has a wide circle of friends.
She loves to socialise and is a keen tango dancer.
But when Heidi opens her mouth to speak, her voice instantly commands the attention of everyone in the room.
A few simple sentences can take severe stammerer Heidi an age to get out.
It's painful to listen to and exhausting for her.
She's no victim though and she doesn't want pity.
In fact the only time her smile fades is if you try to finish off her sentences.
Heidi began stammering around the age of three. Growing up in Billericay in Essex, she had all the therapies, none really worked.
But she hasn't let it hold her back - her outgoing personality is testament to that - so too is a first class honours degree in psychology from the University of Kent.
She has a good job too - working on an older carers project for Age Concern in Norwich.
Despite not seeing her severe stammer as an impediment, Heidi volunteered for the pioneering treatment in America. She is one of the first Britons to try it.
She says: "I suppose deep down I would love a cure or something which helps my stammer."
The treatment is not available on the NHS and costs over £5,000, and there are no guarantees it will even work.
The 'choral effect'
Her speech therapist Mary Kingston says it will not be a miracle cure. "I don't think we should look at it as a cure.
"It is much more like a pair of glasses. It will hopefully ease it. That is what we are both hoping for."
Heidi travelled to America where she was fitted with the electronic implant called SpeechEasy.
It looks like an advanced hearing aid.
Gareth Gates is a famous example of someone whose stammer stops when he sings
Like most stammerers, Heidi can sing in unison without stuttering. The implant mimics that "choral effect" by sending out an echo of Heidi's voice.
It tricks her brain into thinking she is talking along with someone else and unblocks the impediment.
Heidi's initial response was very promising. For an hour she talked fluently - practising reading pages of text; recounting the days of the week, the months of the year.
"I don't feel like Heidi because I am not stammering," she said.
"It is almost as if I am detached. That is a strange person speaking, it isn't me.
"I feel as if I am on a drug because it is making me so relaxed. I am listening to a little man in my ear. I am just not struggling as much. It is just so strange to speak without stammering."
It's not a total cure, says speech pathologist John Haskell who treated her in New York.
"Heidi is starting to hear herself differently. She heard her voice with a slight delay and with a higher pitch speaking with her.
She will have to expect moments of stuttering or blocks, but she is going to learn to deal with it. People around her will have to expect that she is not going to be 100%."
There have been emotional adjustments to make too. Heidi admits she's scared of using the device.
"It will change the way I communicate. It is almost like I have lost my control."
"Now I am more self-conscious. Today it is almost like I am a different person. I know I am not.
"I am trying to listen to the little man in my ear. It is quite hard.
"I go through life and I don't ever have to think about my speech. Now I am having to concentrate.
"It has been a long journey. I am still on that journey. It seems too much now. Too scary to look at what I can do with it. It's still me, whether I stammer or not."
Inside Out: Stammering is on BBC1 East on Monday 11 September at 1930BST or nationwide for satellite viewers on D-Sat 951.