A family whose daughter was born profoundly deaf has been told the Scottish NHS will only implant a device to aid her hearing in one ear.

The Cunninghams, from Glasgow, are battling for one-year-old Hope to receive cochlear implants in both ears - and said they are worried about how she will cope if she is treated on just one side.

Currently, NHS Scotland only funds two implants in special circumstances and infants who are born deaf, such as Hope, are likely to be restricted to one. The devices cost around £17,000 each and patients require close monitoring, particularly during the first year.

John Cunningham, Hope's father, said other countries fund two and that the NHS is trying to save money. Their story comes amid a call to debate whether young people should be prioritised for NHS spending over the elderly.

Mr Cunningham said they believed two devices would help their daughter to communicate. While she would still be able to pick up language with one, he said, she may struggle in noisy places.

"What does worry me is, if she has one implant, she will not get the benefit of being able to concentrate in busy situations," he said. "There may be difficulties in situations where there is a lot of other noise, such as crossing the road. The classroom is a big worry. If there is a lot of peripheral noise, it will be much more difficult for her to concentrate."

However, Agnes Allen, consultant clinical physicist with the Scottish Cochlear Implant Programme at Crosshouse Hospital, said there was not good evidence showing two implants were better than one.

A cochlear implant is an electronic device designed for people who are so severely deaf they gain little or no benefit from a hearing aid. It includes an external component, which contains a microphone and looks like a hearing aid, and an array of electrodes implanted surgically.

It works by directly stimulating the nerves of the inner ear with electrical signals, which the brain interprets and recognises as sound. Guidance on whether young children should be given two implants is being reviewed in England and it is understood the latest draft backtracks on an earlier version which supported two for pre-lingual children.

When a final decision is published, the position in Scotland will be re-examined.

All implant operations on adults and children from across Scotland are performed at Crosshouse Hospital in Kilmarnock. Ms Allen said any patient suitable for one implant would receive it, while there has been a postcode lottery in England with some people struggling to obtain even this level of treatment.

Certain patients are also eligible for two in Scotland. These include people who have lost hearing through meningitis because new bone can grow inside their ears and make future implants problematic. Children with Usher syndrome, which affects hearing and vision, are offered two.

However, Ms Allen said implanting two devices did not offer a double benefit.

She said: "The main reason people want a cochlear implant is for communication and for children, so they can develop speech and language, and people can do that with one." A second device may help people tell which direction a sound is coming from, she said, and manage better when there is background noise, but would still not provide the same range enjoyed by a hearing person.

She added that surgeons had to drill a hole in the cochlear to fit the device. If new treatments for deafness became available, she warned, this could prevent a child from benefiting.

There is no history of deafness in the Cunningham family and they do not know what caused Hope's condition, which was picked up during newborn screening.

Mr Cunningham admitted fighting for two implants was "a gamble for parents". He said: "We could be taking something away permanently, but we have discussed these things at length and we still see a great deal of benefit in bilateral implants." It was frustrating, he added, to be told there was need for more research.

He said: "We would gladly take part in research if that is what it takes."