Music wherever they go — but what is it doing to their hearting?

Press, 26 April 1984, Page 21

Music wherever they go — but what is it doing to their hearting?

By

KEN COATES

They walk, ride bikes, even run, as though in a dream, eyes glazed, a far-away expression on their faces. The only clue is a tiny cassette recorder dangling from a shoulder strap and a miniature set of earphones. They are devotees of one of the world’s biggest teenage crazes in years, “personal stereo,” which blasts out pop music that only the head-set wearer can hear.

Now, concerned at damage to the hearing of young people who misuse the miniature cassetteplayers by turning them up loud for hours on end, some health authorities overseas are pressing for a limit to volume allowed in such machines.

In New Zealand, “plugged-in” youngsters in their own world of pop are either listening for shorter periods, keeping the volume down, or their hearing problems have not shown up yet. But hearing experts here warn that potential for damage does lie in the personal stereos, but it all depends on the susceptibility of the listener to loud music, and the duration and volume of the bursts of sound.

The principal audiologist at the National Acoustics Centre in Auckland, Bill Keith, says: “A few people are probably placing themselves at risk, but it wouldn’t be hordes of teen-agers.” In South Wales, the picture is different. Perhaps the dreary climate and high unemployment drives many more youngsters into a private escape of pop tunes, for long periods, but whatever the reason, the community health chief, Bryn Williams, is worried.

“Young people are going deaf, and they are already seeking help, despite their age,” he says. “The increasing use of these hi-fi units is cause for concern, and the answer is to put a stop to the sale of such equipment.”

It is estimated that around the world, there are 30 million sets now in use, most worn by youngsters travelling in trains and buses, walking through crowded shopping areas, or jogging along country roads.

“They often seem to be in a world of their own, engrossed in the music and oblivious to everything else,” says Bryn Williams. “Certainly, they are oblivious to the possibility of suffering serious damage to their ear-drums.” While the chief audiologist at Christchurch Hospital, Richard Powell, has no direct evidence pointing to the personal hi-fi sets causing hearing damage, he sees them as a possible contributory cause.

The ear needs time to recover from noise, he explains. If a person who works in a noisy environment all day goes home and regularly turns up his personal stereo for an hour or so, and then goes to a pub to sit in front of the band’s speakers all evening, damage to hearing could result.

It is not only the "switched-on” receivers of pop music who are at risk, but also the producers in bands who belt out the beat through giant sound systems close to them.

Players in some New Zealand pop bands aged only in their twenties are becoming partly deaf, and need hearing aids, reports Richard Powell. “They first experience difficulty with sounds of higher frequency and so miss out on some consonants in speech,” he says.

“This means difficulty in communicating with someone where there is bustle and noise, such as in a busy supermarket.” Research at the Radcliffe Infirmary in Oxford, has shown that commercial pop music tapes, played at an average volume on a personal stereo, regularly reach a noise level of 105 decibels.

By comparison, the sound of a pneumatic drill digging a hole in the footpath, three metres from the listener, is estimated at 90 decibels.

In New Zealand, the limit for noise over an eight-hour day in a factory is 85 decibels. In other countries it is nearer 100 decibels.

The Health Department in this

country recommends that no-one should work for a stretch longer than eight minutes exposed to a noise of 103 decibels, without wearing hearing protection devices such as ear muffs.

The sound from personal stereos can be very loud indeed, although the 105 decibels recorded in the Oxford research would be in “peaks,” experts here point out. The continuous or average noise level is likely to be lower. General concern at possible effects of loud music on young people’s hearing is partly a reflection of the objections many people have to the noise of pop music. Researchers have apparently found that if people are enjoying loud music, the chances of their hearing being damaged is reduced. But if the blast of the pop beat and braying amplifiers is making shouted conversation impossible, causing stress, then a greater chance of hearing impairment exists.

The problem of loud pop music is not as big as some claim, says Bill Keith, and it should be kept in perspective. On the other hand, its capability for hearing impairment should not be overlooked with the

improvement in technology each year enabling ever higher levels of sound to be produced. (The bands of the players treated by Richard Powell for hearing problems have been recorded at 120 to 130 decibels of peak noise.) Manufacturers are quick to insist that personal stereo sets themselves are not dangerous, and that only misuse could lead to trouble. The personal stereos have attracted other enemies. Some critics argue they are unsafe for any road user, driver, cyclist, or pedestrian. Scotland Yard describes them as “a real menace” because they might prevent users from hearing a car horn or screech of brakes.

The Ministry of Transport in Christchurch does not share this degree of concern, but a spokesman says he is aware of the potential hazards if concentration is distracted and loud music prevents warnings, such as a car horn, from being heard.

In the American town of Woodbridge, New Jersey, a by-law now makes headphone freaks liable to fines of up to ?50, or 15 days in jail, for “careless use of the road.”

An even more serious complaint has come from Britain’s Britannia Airways, which claimed that a passenger’s personal hi-fi interfered with sophisticated naviga-

tion equipment on one of its aircraft. The incident is said to have happened while a Boeing 757 was flying over Europe. It was reported that the plane strayed 70 miles off course, over the Atlantic.

This was later denied by the Civil Aviation Authority. Britannia bought a similar stereo unit, and tried to reproduce the exact flying conditions, but no similar effect could be discerned.

While the playing of personal hifis is not specifically excluded under New Zealand civil aviation rules, as for example are transistor radios and some calculators, a passenger walking aboard an aircraft playing one would almost certainly be asked to stow it away in case it affected the navigation system. In response to pressure from around the world, at least one manufacturer now includes a special warning light on all stereo players. When the noise level goes over 90 decibels, it flashes on and off.

In Britain, this is welcomed by the Institute of Environmental Health Officers. They believe this kind of reminder will help stop sensible youngsters getting carried away by their music and turning the volume up high. A spokesman says: “We have established people are at risk from these personal stereo systems. The sound levels they can produce would not be tolerated in industry. “The message to anyone using one is: turn it down, or you may soon be needing another personal electronic gadget — a hearing aid.”