Noise-induced hearing loss is the most common reason people lose their hearing. It has been estimated that 15 per cent of those between the ages of 20 and 60 have hearing loss caused by personal stereos, rock concerts or factory machinery.

The damage can be caused by a single exposure to a very loud noise, such as an explosion, but more often it is caused by continuous or chronic exposure to loud sounds over time.

Exposure to these affects the delicate hair cells in the ear. The cells convert sound into electrical signals which then travel to the brain.

Once damaged, hair cells cannot grow back, so hearing is reduced. One theory is that the force of vibrations from the noise damages the cells.

The new pill is based on the idea that these vibrations cause the release of destructive molecules called free radicals into the bloodstream. These free radicals damage the hair cells.

Researchers had thought that antioxidants - chemicals that protect against this cell damage - might prevent hearing loss only if the antioxidants were given before noise exposure.

But research at Michigan University has shown that when the antioxidants were given up to three days after noise exposure, hearing loss was significantly reduced.

However, if treatment was delayed until five days, it was not effective. In the new trial starting this month at Michigan and five other universities in the U.S., Spain and Sweden, more than 300 people will be given the pill, which comprises antioxidants and other compounds, to assess its protective effect against different types of noise.

Overexposure: More people are getting hearing problems due to listening to loud music with headphones regularly
Participants include young adults exposed to moderately loud music from personal stereos, factory employees working with loud machinery, soldiers exposed to loud gunfire, and Nato airbase workers who are surrounded by aircraft noise.

The effects of the pill will be compared with that of a placebo. The 'real' pill will contain three antioxidants - betacarotene and vitamins C and E - and the mineral magnesium.

The antioxidants will tackle the damaging free radicals, while the mineral magnesium boosts blood supply.
Research has shown that in people exposed to loud noise, blood flow into the ear falls because of free radical formation.

Noise-related hearing loss is a growing problem - two months ago the European Union's scientific committee on emerging health risks warned that more than a million Britons could go deaf through listening to their MP3 players at a high volume for too long.

Dr Ralph Holme, of the Royal National Institute for Deaf People, said: 'This is an exciting clinical trial. It will shed light on whether taking antioxidants as a dietary supplement can help prevent this type of hearing loss.
'As well as people limiting their exposure to damaging levels of noise, it's vital that medical treatments are developed to protect hearing from loud noise.'

The trial is expected to take up to two years. Then if the pill is shown to work in larger trials, it could be produced quickly and easily for general use because the ingredients are already widely available.

Source: Daily Mail