Forget interactive whiteboards and PowerPoint presentations. The most charismatic classroom performers rely on something far more magical: the sound of their own voice. When teachers drone on, children switch off. It's a problem that made the headlines in summer when the general secretary of the Professional Association of Teachers, Philip Parkin, told its annual conference that teachers should receive voice training from out-of-work actors to improve their ability to hold the attention of bored children.
Teachers, he said, had to be part-performers. "We are there to deliver the curriculum, but the way in which we do it and the way in which we present it has a big impact on learning."
The problem is that while most teachers recognise the voice as the tool of their trade, many treat it as a pneumatic hammer rather than a sculptor's chisel. "I start each session by asking teachers what they want from my workshops," says Lesley Hendy, a voice tutor who works widely in schools.
"The answer is always the same... they want to learn how to shout."
Being able to raise your voice - or to "project" - is a useful skill.
Teachers need to be heard clearly by everyone in the room, and the occasional clap of vocal thunder, used sparingly, can silence a class in an instant. But constantly talking too loudly can be self-defeating, increase background noise, and make the classroom a more stressful place. Trying to talk loudly is also a reason why teachers can sound monotonous. When the voice is produced in a relaxed way it nearly always has colour and variety.
As soon as you start to strain, muscles around your vocal cords tense up, your breath flows less freely, and your voice becomes stuck in a particular pitch, which is less interesting. "You may be heard, but you won't necessarily be listened to," says Lesley Hendy.
With the right breathing and relaxation it's possible to project safely, but teachers who need to shout are likely to be anything but relaxed.
Without proper technique you run the risk of damaging your vocal cords.
"You need to be in control of your voice," says Lesley Hendy. "If you're shouting a lot, then you're not in control."
All good storytellers know that the best way to draw people in is to lower the volume, rather than to raise it. You can make that easier by arranging your classroom in a way which brings your audience closer. Plenty of eye contact with individual pupils can also help you to sound more like a real person and less like a station announcer. And if the acoustics are unhelpful, focus on clear articulation rather than just talking loudly. As well as varying the volume, it's important to modulate the pitch and pace of your vocal delivery. The human voice is capable of a vast range of notes, yet teachers, like most people, tend to stick within a limited register. When talking to a class, it's easy to adopt the dull, safe voice of authority, which soon becomes a habit, leading to the teaching drone which causes pupils' attention to wander. "Experiment with your voice, play around with it, try new things," urges Maureen Speller, a voice tutor who has worked with trainee teachers at Exeter university. "You don't need to copy others; it's more important to discover your own voice, and explore it to the full."
With proper instruction most people can extend their vocal range, improve their resonance, and develop a rich, interesting voice. "But there's no quick fix," warns Lesley Hendy. "It's like learning to play a musical instrument, it takes practice, patience and hard work. You need to have the right training."
Philip Parkin's suggestion that this training could be provided by out-of-work actors is sound. As well as passing on the basics of good breathing and posture, and the secrets of dramatic pauses and comic timing, actors could also offer teachers a tip or two about saying the same lines over and over, while making them sound brand new. But perhaps the single most important thing is to ensure your voice stays healthy. Teachers talk for around 60 per cent of their working day, so a lack of proper technique is likely to cause problems. Recent studies have shown that almost half of new teachers suffer voice problems in their first year teaching, while around one in eight patients at voice clinics is a teacher.
And when there are problems, it's not just the teacher who suffers. New research by Jemma Rogerson, a speech therapist in Lancashire, shows that when a teacher's voice is under the weather, pupils pay less attention to what's being said. Children were played recordings of teachers' voices, then asked questions about what they'd heard. Those who'd been listening to teachers with hoarse voices remembered less of what they'd been told.
"Voice training is often seen purely as a health and safety issue," says Lesley Hendy. "But this research proves it's about more than that. If you train teachers' voices, then you improve their ability to communicate. That means a better classroom experience for everyone."
EIGHT STEPS TO A MORE INTERSTING VOICE
Book a workshop
There's no substitute for expert tuition. The Voice Care Network can put you in touch with voice tutors in your area. www.voicecare.org.uk; 01926 864 0000.
Keep your voice healthy
Drink plenty of water, and make sure that your classroom is well ventilated. Avoid eating spicy foods late at night. If your voice feels sore or tired, then rest it.
Warm up your vocal cords
A morning warm-up will get the best from your voice. Start with gentle stretching to relax neck and shoulders. Hum a note in the middle of your range, then a note or two above, and a note or two below. Repeat with different starting notes. Blow out through your lips, making them wobble.
Say "grrrrrr" a few times, rolling the "r" as much as possible. Recite a tongue-twister. You're ready to go.
Extend your range
Count from one to 10, rising in pitch slightly with each number. Then count back down, lowering your pitch. Repeat a few times. Try stopping at random numbers and saying a line of poetry in that particular pitch.
Wake up the resonators
Sound is amplified when it resonates in the chest, mouth, nose and head.
Experiment by trying to get different sounds to resonate in different areas. A deep "hah" should vibrate in the chest, while an "ung" sound will probably feel nasal. A well-balanced voice uses all the resonators.
Vary your volume
Recite something you know by heart. Begin quietly and gradually get louder.
As you increase volume, breathe from the diaphragm and make sure you have plenty of breath to "power" your voice. Don't shout - if you feel yourself straining, stop.
Control your breathing
Take a piece of text, and say the first word. Breathe. Say the first two words. Breathe. First three words. Carry on, making sure that you take an appropriate amount of breath each time. When you start struggling, stop.
Improve your articulation
Focus on pairs of consonants that sometimes become blurred: such as d and t, or p and b. Try repeating sequences of vowels and consonants, enunciating clearly. For example, say Ad, Ed, Id, Od, Ud then follow it by saying At, Et, It, Ot, Ut. Don't rush. Try to be precise.