Richard Cox, 31, helped his wife Hayley give birth to early arrival Emilie, crediting staff from the Scottish Ambulance Service with saving her life.
His wife had gone into labour at night and before he had the chance to dial for an ambulance Emilie had been born.
When she was born he rang the Scottish Ambulance Service and the call-handler gave him instructions to cut the umbilical cord.
But Mr Cox had no choice but to use his earphones to tie up the cord.
The bank worker said: “I rang 999 and the call-handler said I needed to find a bit of string – such as a shoelace – to tie up the umbilical cord.
“The only thing I could find was my iPhone earphones – I tied them to the cord and it was fine. The call taker deserves all the credit. All while this happened, she was asking ‘is the baby breathing, is the baby OK?’
“With all the noise in the background, she could have lost her cool as well.
“We had it in our mind that the child was not going to be breathing.
“All the actions of the Scottish Ambulance Service ensured that our little girl survived and I can never thank them enough.”
Tying the umbilical cord is vital to ensuring a newborn’s survival, preventing the mother and the baby from developing a potentially deadly infection.
Mr Cox said everything he did was a “natural instinct”, and once everything was fine with their newborn he calmed his son.
The couple were at their home in Rosyth, Fife, when Mrs Cox started to experience “intense” pain, which lasted about 45 minutes.
The couple’s first child, two-year-old Liam, was asleep at the time.
Mrs Cox, 32, was in the bathroom when she called out for her husband.
The emergency call was taken by Jodie Craig and an ambulance was dispatched by supervisor Lynne Walker.
Emilie was born at 1:25am weighing 3lbs 14oz on 8 January. In contrast, Liam was born weighing 8lbs 9oz.
Mrs Cox added: “Our other child Liam was asleep and woke when he heard her crying.”
Mr Cox said: “I cannot remember if she was head first or what. The main priority was making sure she was breathing, and making sure her face was wiped.
“I did not appreciate she was born until the ambulance arrived. It’s amazing how your instinct takes over.”
Six months on from the birth, the family says Emilie is doing well and now weighs 16lbs 12oz. She came home after a few weeks at the special care baby unit in Kirkcaldy.