The bell is the last ringing sound most teachers hear each day. But for tinnitus sufferers the ringing in their ears is permanent. Tinnitus, which comes from the Latin tinnere, means to ring or tinkle. To a non-sufferer, these symptoms don't perhaps sound like those of a debilitating illness. But for 10 per cent of the population, the reality is a constant noise in their ears, sometimes a whooshing or humming sound.
Although it is more common among elderly people, the British Tinnitus Association (BTA) is worried enough about an increased risk among children to have published an education pack for schools, Don't Turn it Off, Turn it Down. It explains how loud music can affect hearing and cause tinnitus, and that any personal stereo that others can hear when they're more than two metres away is dangerously loud.
Tinnitus has a number of triggers, including stress, ear syringing, head and neck injury and loud noise, although it can also be a side-effect of medication. Sufferers also often have damage to the tiny hair cells in their inner ear, which interrupts the normal transmitting of signals sent to the brain. The brain picks these up as a sound - tinnitus.
Val Rose of the BTA, who put the schools pack together, says it's obvious that teachers are at risk of developing hearing problems like tinnitus. "Think about the noise 30 screaming kids can make in a classroom, and all the hard surfaces which exaggerate noise."
Former science teacher Martin Hayes (not his real name), 5l, left the profession two years ago because of tinnitus. He developed it 16 years ago following a motorbike accident in which he suffered concussion.
"I thought I had an infection, and was given ear drops," he says. "But finally, I saw a specialist and was diagnosed. I have a noise like a dentist's drill in my ears constantly - it's louder than any other noise, including the television."
Martin taught with tinnitus for 14 years, and welcomed voluntary redundancy when it was offered. "In class, there was this terrific noise to listen to before I could hear any pupils. I had real difficulty if they were sitting at the back of the class. It was very stressful, which in turn made the tinnitus worse. The condition made teaching unbearable, especially if I had a noisy group, but I didn't want anyone to know that I had a hearing-related problem because there is a stigma attached. I hated having to ask students to repeat questions - sometimes I gave them wrong instructions if I misheard them."
He found the condition embarrassing, and it made him feel old. "Students don't differentiate between deafness and tinnitus." Martin's name has been changed here as he feels his current employer, a local training and enterprise council, might become concerned about his condition. He now uses so-called tinnitus maskers, small wearable generators which create a white noise which in theory masks the tinnitus. "You try to get your brain to appreciate that noise is normal, by masking your tinnitus with a sort of rushing noise. It relieves it a bit but it doesn't get rid of it," he says.
Gareth West, 5l, from Pontypridd, taught design technology at a comprehensive for 28 years, and is convinced his tinnitus was caused by the sound of the circular saw he used for woodwork classes. "Back in the Seventies, it was up to the teacher to protect him or herself. It's different now, but my damage was already done," he says.
He first noticed something was wrong in l99l, but he didn't know his condition had a name. His hearing began to deteriorate and he was diagnosed with tinnitus. "The closest sound to what I hear i when you're trying to tune a radio in, the crackling between stations. It's incessant, although now and again I get a crescendo."
He says it's as loud as "someone shouting at you constantly". He found the biggest problem in class was communicating with one student while others around made a noise. "I'd have to be standing one foot away from the person I spoke to. It was impossible, repeating everything. Because people can't see tinnitus, they feel it doesn't exist, and I found responses to it quite hurtful. I can't really say we suffer in silence because that's the one thing we can never have, but it is an isolating condition."
Gareth is now on the council of the BTA, and chairs a self-help group for sufferers who are mostly 45-plus - the generation which grew up during the loud rock concerts of the Sixties. "It's a vicious circle. You get stressed, that causes depression, which makes the misery worse." He now works as a driving instructor and is undergoing "habituation therapy", which means using maskers.
David Baguely, who runs a tinnitus clinic at Addenbrooke's hospital in Cambridge, sees a lot of teachers with the condition. "People are more interested in tinnitus now," he says. "It was seen for years as a rather non-glamorous area of hearing science and there was a lack of awareness. Now I'm seeing about 500 new patients every year."
He is certain that stress rather than excessive noise causes the condition in many teachers, "except teachers of subjects like metalwork".
He describes the classroom environment as "uncomfortable" for sufferers. "If you get it, you have to be very strong and not panic. Acute distress will make it worse. The best thing to do in the early stages is to avoid silence, as you will then focus on the tinnitus."
The BTA recommends the use of "environmental maskers" such as a ticking clock, a radio, an electric fan or an open window to let some noise in from outside. It also advises relaxation techniques and exercise to promote a sense of well-being, which can help sufferers ignore the symptoms. Keeping your mind active and being absorbed in an enjoyable pursuit may stop you thinking about the condition.
Nurses, including those within schools, are the next group the association plans to target. A researcher for Nursing Standard magazine found schoolchildren who described the level of music they like as being so loud the ground shakes. One l4-year-old, talking about how he felt after leaving a club, said: "Sometimes when I go home afterwards, it feels like my ears have been muffled, like they're full of cotton wool. I can't speak to anyone and it feels like my voice has gone."
The British Tinnitus Association, 4th floor, White Building, Fitzalan Square, Sheffield S1 2AZ. Freephone: 0800 0l8 0527.Website: www.tinnitus.org.uk DON'T SUFFER IN SILENCE
* Avoid silence, as this will make you concentrate on the noise in your ears.
* Certain foods or drinks can make it worse: avoid red wine, caffeine, tonic water.
* Do as much as possible to aid relaxation: massage, exercise or aromatherapy are all worth trying.
* Try ear plugs to avoid loud noise. Good ones can cut out up to 30 decibels.
* Good posture is important, as it makes it easier to breathe properly, which in turn aids concentration and relaxation. Try the Alexander technique, yoga or tai-chi.
* Try not to worry about tinnitus, as stress and tension can make the noise seem louder.
* If you have hearing loss as a result of tinnitus, a hearing aid may be helpful. It will not only improve your hearing but could help to reduce the intrusiveness of the tinnitus by amplifying the everyday noises you have been missing which, in turn, will help to cover the internal noises. (If your environment is quiet, you will need to add some noise for the aid to amplify.)