Fire alarms would be more effective at waking sleeping children in the event of a blaze if they were fitted with the sound of their mother’s voice, a new study has shown.

Children’s hearing is different to that of adults, and British research last year showed that 80 per cent of under 13s do not wake up to the high-pitched sound of a normal home smoke detector.

To find a way round the problem, US researchers at Sleep Disorders Center at Nationwide Children's Hospital in Ohio, tested four different types of fire alarms to see which was best at waking youngsters.

They tested three alarms that used the mother's voice in addition to a high-pitch tone smoke alarm commonly used in homes on 176 children between the ages of 5 and 12.

The results showed that the alarms using the mother's voice woke up 86-91 per cent of children and prompted 84-86 per cent to escape from the bedroom, compared with 53 per cent awakened and 51 per cent escaped for the tone alarm.

"These new findings put us one step closer to finding a smoke alarm that will be effective for children and practical for parents," said Dr Gary Smith, lead author of the study and director of the Center for Injury Research and Policy at Nationwide Children's Hospital.