Techniques in the classroom may vary, but one thing is common to all teachers: they talk a lot. This is not just social chatter, of course, but the use of the voice as a fundamental tool of the trade. Although teachers may recognise the hidden potential of this invisible resource, many probably also experience some of the difficulties that accompany prolonged use.

A short article in The TES (November 20, 1998, “Teachers are shouting out for voice training”) elicited more than 500 enquiries to the Professional Association of Teachers from teachers with voice problems. “There was a sense of disappointment that they had never had any voice training,” says the association’s solicitor David Brierley. “It is clear this is a problem that is costing many teachers dear.”

Although there are encouraging signs that there is a need for professional support in this area, it is also true that, at a basic level, improved care and use of the voice can be achieved by following simple guidelines.

For many teachers the day-to-day stress of a hectic schedule can have an adverse effect on the way they speak, creating bad habits that are hard to break. Anxiety causes people to take more frequent, shallow breaths. When your breath is shallow, your abdominal muscles do not function as they should, and it is the muscles in your neck and throat instead that are left to do all the work. When these muscles are given too much to do, they become tense, and this in turn puts pressure on the vocal cords. For teachers having to talk for long periods, especially over noise, this tension can have a damaging effect on the voice.

Poor posture - whether it be the classic confrontational pose of standing before a class with your chin jutting forward and your jaw tense, or simply too much time hunched over a desk, marking - can also hinder over the flow of breath and create tension.

Hot and stuffy classrooms are another potential danger. Your voice will work best in a moist, well-ventilated atmosphere (experts recommend drinking at least a litre of water a day to prevent dehydration). And the staffroom cup of coffee makes this even worse as caffeine can cause vocal cords to dry out more quickly.

A simple thing you can do at the end of a long, hot day if your voice feels tired and hoarse is to inhale steam from a kettle that has gone off the boil. Steam eases and rehydrates the voice - which is why people sing in the shower.

Many of the people referred to voice specialist Jane Thornton, based at the Royal Hallamshire Hospital in Sheffield, are what she terms “professional voice users” - teachers, vicars, lecturers and telephonists. At present she has five teachers among her patients. “Usually there’s a mixture of problems. I recently treated one teacher whose problem was caused by dust from the chalk she was using on the blackboard. It was making her clear her throat all the time. When you do this, the vocal cords bash together quite violently.”

The vocal cords or glands responsible for vocal production are a remarkable piece of apparatus. They consist of two bands of muscular tissue in the larynx that vibrate as breath passes over them to produce sound. They are usually about 15mm long in women and 20mm long in men, but their tension, width, thickness and length can all be varied to produce an array of sounds. When used correctly, they are highly efficient. If used incorrectly, however, they are prone to wear and tear.

Patsy Rodenberg, head of voice at the National Theatre, London, warns that too often with these muscles it is a case of out of sight, out of mind. “Speakers will happily risk vocal damage long before they would hurt themselves physically in other ways. Many teachers take it for granted that their voice will hurt over the weekend after five solid days’ teaching, but there is no reason why it should.”

Whereas actors and singers are fiercely protective of their voices, many teachers struggle on with vocal problems, rather than seek help. One of my former colleagues, an excellent and vocally dynamic teacher, often suffered throat infections but still insisted on entertaining his classes in his usual manner, even if his voice was reduced to a hoarse whisper. He thought that he was saving his voice by whispering, but in fact this was the worst thing he could have done. If your voice is damaged, rest it, but if you really must speak, then try to support the voice by taking good breaths and speaking properly.

Correct breathing - deep, relaxed breaths that come from the diaphragm - is the basis of good voice production. Clear articulation can often be more important than increased volume, but inevitably there are times when teachers have to raise their voices or talk above noise. In these cases, a good vocal technique is essential. For a games teacher having to shout instructions across a playing field, good, relaxed breath support will protect his or her voice from damage. Any tension in the neck or throat will soon result in soreness.

Part of the problem is that many teachers simply don’t know how the voice works and how to get the best from it. In 1993 Roz Comins, previously involved in voice training for actors, founded Voicecare Network UK for teachers. A registered charity, Voicecare gives workshops, courses, booklets and individual coaching in voice production. “Voice can be a very personal thing,” says Roz Comins. “People who have problems often think ‘Oh no, what’s wrong with me?’, but usually it’s just a question of knowing more about it. If you’re a sportsman and you have a problem with a muscle, you know you can go to a physiotherapist, but people who have problems with the vocal muscles aren’t always sure what to do.”

Her organisation has encouraged universities to include more work on the voice in their teacher training courses. But this still falls far short of the voice training offered to many other professional voice users.

An attentive audience is what every teacher seeks, but many simply do not know how good vocal technique can help achieve this. For example, a teacher who feels a class is being unresponsive may be tempted to “push” their voice. This not only gives the vocal cords a tough time, it also tends to create an aggressive sound which can alienate an audience. People listening to a strained voice will get the impression that they are being talked “at”, rather than “to”. A relaxed voice is more flexible, varied and makes easier listening.

So it isn’t only for health reasons that teachers need to be aware of their voices - an interesting voice holds interest. Most people only use a fraction of the potential range of their voice, and teachers can be more guilty of this than most. The temptation, says Patsy Rodenberg, is always to sound like a teacher. “As adults, we adopt roles that lock our voices into place, and this is especially true of professionals like teachers.” It is all too easy to lapse into the “safe” voice of authority, which is usually a rather dull one.

Our voices can be accurate reflections of our personalities and emotions. If someone is enjoying their teaching, then they are unlikely to sound dull, and if their voice is in good working order, then they are more likely to be enjoying their teaching. “When your voice is working well, you feel better in yourself, more confident and relaxed,” says Roz Comins. “If your voice is healthy, other things will fall into place.”

Steven Hastings is a freelance actor and writer, and a former teacher of English and dramal Voicecare Network UK, 29 Southbank Road, Kenilworth, Warwickshire CV8 1LA. Tel: 01926 864000.l A factsheet with support information for teachers experiencing problems is available from the Professional Association of Teachers (PAT), 2 St James’ Court, Friar Gate, Derby DE1 1BT. Tel: 01332 372337.l The Voice and Speech Centre, 8 Great Guildford House, 30 Great Guildford Street, London SE1 0HS. Tel: 0171 620 1492.l ‘The Right to Speak’ by Patsy Rodenberg (Methuen) is available from bookshops