HEALTH / Second Opinion

HEARING is much more easily damaged than sight. Noise damages hearing, and we live in an increasingly noisy world. According to a recent Lancet article, young people's ears today are ageing up to three times faster than their parents' did. By contrast, abuse of the eyes by reading in poor light or peering at computer screens does no harm. The main danger to vision is overexposure to sunlight, increasing the risk of cataract.

Primitive human beings heard few loud noises, with a few exceptions such as thunder and waterfalls. Groups such as the Bushmen of the Kalahari have amazingly acute hearing. Nevertheless, in all societies hearing shows a steady decline with age and urbanisation.

Ear specialists are worried by the acceleration of this natural ageing process: many of today's 15-year- olds have hearing levels to be expected in people aged 45. The Lancet quotes Dr Eric Le Page of the Australian National Acoustics Laboratory, who warns that within 10 years 50 per cent of men and 15 per cent of women will be complaining of impaired hearing - nearly double the present numbers. In 20 years' time, he says, the proportions will be 78 per cent and 25 per cent.

The damaging effects of loud noise have been known for centuries. All military gunners and riveters eventually became deaf, and many other trades left workers with damaged hearing. Ear defenders are now recommended for people working with chain saws, pneumatic drills and similar machines.

In the past 10 years or so, continuous loud recorded music has become pervasive in pubs, discos and cars. Ear specialists warn that, if other people can hear a personal stereo, it is dangerously loud.

Men have worse hearing than women. They bombard their ears with noise from motorcycles, boat engines and guns; those working in noisy occupations fail to wear their ear defenders, regarding them as wimpish; and there is a macho culture of excessively loud music.

The current generation of teenagers is probably exposed repeatedly to higher noise levels than any in the past. Within a few years there will be an epidemic of hearing loss in people in their 20s and 30s. The evidence suggests that the harmful effects of noise are cumulative, and such damage to the inner ear is not reparable. By the time someone realises he or she is deaf, little can be done. This impairment of hearing matters, because deafness is in many ways more socially handicapping than poor vision. The real problem is that nobody has yet found a way of persuading teenagers to take greater care of their ears.