Using your mobile over an hour a day 'can harm hearing'

Research shows that those who regularly use their mobile for longer than an hour a day find it harder to hear - with words starting with the letters s, f, h, t and z proving particularly troublesome.

The study, presented to an ear, nose and throat conference in the U.S. this week, comes as mobile phone use in Britain soars to record levels.

There are 70 million handsets in use in the UK, which are used to make a third of all calls.

The latest research compared the hearing of 100 mobile phone users aged between 18 and 25 with that of 50 others who did not use mobiles.

This showed a link between longterm regular usage and hearing loss, with those who used their mobile for more than an hour a day for more than four years tending to find it harder to distinguish sounds.

The problem was particularly noticeable in the right ear, to which most people hold their phone.

High-frequency sounds, such as those made by the letters s, f, h, t and z, were most likely to pose a difficulty, making it hard to distinguish between words such as hill, fill and till.

Researcher Dr Naresh Panda said it is possible radiation from longterm mobile use damages the inner ear.

Early warning signs may include a warm feeling in the ear, ringing in the ear or a feeling it is clogged up, the American Academy of Otolaryngology's annual conference heard.

Dr Panda, a ear, nose and throat specialist from India, said the small number of people studied means more research is needed to confirm the link.

"Our intention is not to scare the public," he said. "We need to study a larger number of patients."

However, the researcher, who owns a mobile but uses it sparingly, urged caution.

"We should educate the public only to use them when necessary," he added.

The Mobile Operators Association, which represents Britain's mobile phone companies, said independent scientific reviews carried out in the UK and around the world had "consistently concluded that the weight of scientific evidence to date suggests that exposure to radiowaves from mobile phone handsets and base stations does not cause adverse health effects".

Last week, the results of Britain's biggest-ever study into mobile phone safety were published.

It found no short-term harm to the adult brain , but a "very slight hint" of a raised risk of some types of brain tumour among those who had used the devices for more than ten years.