A mum has spoken of the amazing emotional moment when her deaf baby boy heard for the first time.
Oliver Bosch, 19 months, was born without vital nerves in his ears - meaning he was profoundly deaf and could not benefit from even the most advanced hearing aids.
But now, thanks to the incredible generosity of well-wishers who raised £60,000 for an implant operation, Oliver has heard his first ever sounds.
Mum Jemma, 37, from Dundee, said: "It was very emotional when the implant was switched on and Oliver reacted to the sound of the drum.
"My husband Ben and I promised each other that we would try not to cry and we just about managed to hold it together.
"We've been on quite a journey and we both know that if we'd waited just a few more months it could have been a different story as it might not have worked.
"It is a long road ahead and we still need to raise thousands more for all the speech therapy he'll need. But we've now been told that by the age of five, his hearing should be at the stage where he'll be able to have conversations on the phone.
"He'll be able to go to a mainstream school, which is something we never thought would have been possible before.
"We're absolutely overwhelmed by the generosity of people who have donated and fund raised and we want to have a big party to say thanks to them - they've given us the best gift ever."
Doctors discovered Oliver was deaf four months after his birth in July 2011 but reassured his parents he would be able to hear with the help of hearing aids.
But Jemma and husband Ben, 29, were devastated when tests revealed Oliver's auditory nerves were missing completely and that surgery was his only hope.
Jemma said: "We were devastated when we first found out what was wrong with Oliver. "The thought of your child never being able to hear or speak is heartbreaking - all you want is for them to say 'mummy' and 'daddy'."
The couple were told by doctors their only hope was to send Oliver for an expensive operation at a leading clinic in Verona, Italy.
But they had just six months to come up with the cash or it would be too late.
Thanks to donors - including a £30,000 mystery donation - the couple raised the money in time, giving the go-ahead for surgeons to fit Oliver with a special electronic device to stimulate his brain stem.
When the device - known as an auditory brainstem implant - was switched on, Oliver instantly reacted to the sound of a banging drum.
Scientists believe the procedure is largely ineffective on children over the age of two because their brains have already adapted to total deafness.
Oliver faces years of speech therapy but doctors are confident that he will still be able to learn to communicate normally and could be holding full conversations before he reaches school age.
Jemma said: "It sounds so silly, but I used to worry so much that Oliver wouldn't be able to go to the pub with his friends when he turned 18 because he wouldn't be able to hear anything. I just feel so relieved that he won't be so left out.
"We just want to thank everyone who has helped us get to this stage."