It's not just the complimentary beakers of lukewarm orange juice and trays of sandwiches that go to waste.

By the time the typical business presentation drones to an end the interest levels of the average listener will have curled up far faster than the crusts left for the cleaners.

The glazed expressions elicited by this army of Power Point-crazed middle managers costs the country about £8bn a year in wasted time, a study suggests.

Why then, if there must be meetings, are they so often deathly dull?

Dogged belief

Max Atkinson, who teaches public speaking techniques to business folk, points the finger of blame at slide shows.

"In a lot of organisations it's not regarded as a proper presentation unless there's slides," he says.

This dogged reliance on "visuals" detracts from a speaker's eye contact with the audience. And used as a support by the nervous speaker, gimmicks become more important than delivery and enthusiasm for the subject.

"The extraordinary thing is that even people who don't like being on the receiving end when they're sitting in an audience still use the same slide-dependent approach when making presentations themselves," adds Mr Atkinson.

Travel expenses

A visiting professor at Henley Management College, he has calculated that if the average £30,000 a year manager spends one hour a week in meetings they don't attention, the total cost to British industry is £7.8bn a year.

Include preparation time, the cost of providing refreshments, hiring venues and equipment, travel expenses and other assorted expenses and the figure grows even more.

Yet still this self-defeating cycle continues, with thousands "attending presentations, from which they are getting little or no benefit".

Another guilty party is those who, in true David Brent style, insist on telling bad jokes in a desperate attempt to keep the audience on-side. Others constantly fidget, fail to make eye contact or use their normal speaking voice when more attention should be paid to intonation and pauses.

Nobody is immune from the danger of being coerced into attending a boring meeting, says Mr Atkinson, but those likely to be addressed by finance directors or the IT department are in particular danger, he says.

Bubbling along

So can the British boardroom be rescued from these legions of monotone, fumbling Power Point diehards?

Mr Atkinson has a few tips for those who want to up their game. The ability to use metaphor, storytelling and rhetoric help keep interest levels bubbling.

And nothing is more important than the speaker having a passion for their topic.

"There's no such thing as a boring subject, only boring speakers," says Mr Atkinson. "A year ago I heard a guy give a speech about the history of pensions and he had 800 people rapt for an hour."