Tony Tysome hums and cackles with students on a blue gym mat while a world expert in voice training sets the right tone It seems as if I have stumbled into a clearing in some magical forest, populated by weird and exotic creatures and birds. I can hear them calling to each other from the branches above and the forest floor. They are clicking, cackling, shrieking "wo! wo!", uttering hollow laughs, chattering, whining like jet engines, rolling their tongues, and repeatedly humming like a swarm of overgrown bees.
But if I open my eyes, the scene before me is more like a yoga class. A group of about a dozen mature students are lying on blue gym mats, their eyes shut, arms resting by their sides, some with legs tucked up. Standing over them is the lean, almost gaunt, figure of David Carey, one of the world's leading experts in voice training.
"It is essential that you stay awake," he advises his apprentices, some of whom are continuing a yawning action from the previous jaw-limbering exercise. Now, like a beardless Gandalf employing soft, assuring tones reminiscent of a children's television narrator, he conjures new sounds from his flat human voice machine.
"I want you to observe yourself, and tune in to your breath," he says. "Think about the journey that the breath takes as it travels in through your nose, through the pharynx, larynx, and trachea, the lungs.
"Imagine you are a fibre-optic lens that can follow the breath down. Think about, if you were that small, what the cavity of the nose would look like."
It is the kind of thought the average person tries to avoid just after lunch. But earlier, Mr Carey, who heads Europe's only postgraduate diploma/MA voice studies programme at the Central School of Speech and Drama in London, had told me how such exercises are an indispensable part of learning to maximise the voice's potential for singing, acting, public speaking, or lecturing.
He explained: "We have to ensure that the body itself is in a good state, and there is no undue tension, which can affect both breathing and the production of the voice. The voice is powered by the breath, so working on that is essential."
I observed that this regime appeared far removed from a popular perception of voice training, pitched somewhere between Pavarotti and Pygmalion. Mr Carey agreed: "We have come a long way since Henry Higgins."
In the class, Mr Carey has instructed his students to "initiate a little hum to chart the breath's journey" and to "think of a colour to associate with that sound and give the sound you are producing the quality of that colour".
Now it seems as if someone's cat has walked onto an electronic keyboard, stepped on the "synthesised voice" button and then sat on the keys. Surprisingly, the result is far from a cacophony.
The quality of the sound is as warm and hypnotic as a humming top. More colours and textures flood in as Mr Carey asks the assembled company to "imagine you have a whole palette of colours, and on the ceiling there is a canvass. But the only brush you have is an air brush - your voice."
Suddenly, it is like a mad house. A telephone is ringing, someone is muttering to themselves in the corner, there are animal sounds, ooooohs, more humming, and a clacking tongue.
Mr Carey brings the creation to a finale, and then invites his co-creators to "sign your name in sound to this masterpiece".
The sound signature airbrushed, the students are now called on to "stand back and look at it (the masterpiece) in your mind's eye", think of a short title, and whisper it over and over. As the company follows orders to stand up and turn up the volume, I find myself straining to eavesdrop on a dozen private conversations.
The straining is shortlived. Mr Carey halts the babbling, and enlists volunteers to tell us all their titles. As one would expect, each is announced in a clear, studied tone: "Paradise"; "Scary Rides"; "Dominatrix"; "Seaglass".
Professor Higgins would have been proud.