They demand rather more attention than the cultured drone of the average audioreader

They demand rather more attention than the cultured drone of the average audioreader. Driving round Shepherd's Bush roundabout just as Spiderman engaged in a vicious duel with Dr Octopus above the heads of a gasping crowd, I was myself nearly exterminated - by an all too real ambulance charging at full tilt. I had assumed that its blaring siren was just part of the audio action.'Peter Pan' and 'The Amazing Spiderman' are now on cassette (BBC pounds 7.99) 'Judge Dredd' is on Polygram (pounds 7.99) 'Batman: Knightfall' broadcast by Radio 1 in April. East, it was said, met West at Port Said, where P&O liners berthed and passengers, when not watching gully-gully men pull live chicks out of catamites' ears, bought "genuine'' camel saddles or Egyptian antiquities of dubious provenance. Gradually, over the years, the boundary shifted relentlessly eastward to hit the buffers at its inevitable destination, China.

The Celestial Kingdom of terracotta armies, silk and jade has been invaded by an alien and ugly culture. It first struck me in winter 1993, in Wuzhou, Guangxi Province It was late evening. I was seated at a food stall in the street, dining on stewed dog with a Chinese friend. Scarlet paper lanterns hung in the arcades, coolies passed with laden poles, a man went by taking his canary for its constitutional.

We could have been in China at any time in the past two centuries, save that from a nearby doorway wafted the unmistakable strains of someone trying to sing Are You Lonesome Tonight? Where once the West suborned China with opium, now it does it with crass vulgarity and tawdry commercialism although, in truth, it is not just westerners infiltrating China but her old enemy, Japan, too. Just as she demoralised China in the 1920s with morphine, so now is Japan undermining her with that insidious export, karaoke. But the sing-along joint is just the tip of iceberg of China's rottenness. Corruption is all-pervading, starting in Beijing and seeping throughout society until it reaches its last and hardest-hit victim, the peasant.China is still a nation of peasants: 45 years of Communism have not greatly altered their lot.

After a brief ideological honeymoon, they have slid back to the position they always held, exploited by everyone. "I've always liked a layering approach with effects," Maggs says. "What they call 'Foley', after the Hollywood sound technician George Foley who moved cinema on from spot effects to a continuum of different sounds added on afterwards. Surround means you can use these far more effectively - instead of running into each other like watercolours, they stay distinct."Maggs settles me in the central "pilot" seat and, muttering lovingly over his favourites, selects a CD of effects A second of action can have half a dozen different elements. "Dredd / mo'bike / start" combines a squeaky chain, two kinds of depth charge, revs from a Harley Davidson, a jet turbine, a skid and Concorde.I find myself squawking Lois Lane-like in capitals and exclamation marks. "UNBELIEVABLE!!! But how can you HEAR X-Ray vision? Or Kryptonite, fer Krissake? Or SQUIDGY STOMACH?" He plays them I concede defeat. Move the mouse, and colour squiggles show the mixer just what is happening to all the different elements being built into the track.

They can be reduced and enlarged to be seen by the hour or millisecond, cut and pasted like words on a word processor.One of the advantages of Dolby Surround is hugely improved clarity. Never mind sound without pictures; this is pictures of sound. A cupboard holds more props - a roll of carpet labelled ''BODY'', various mighty staves and a cloak of invisibility.In the control room next door, the console is like the flight deck of a Boeing 727 A PowerMac is running a programme called ProTool. Maggs is a smiley man in his late thirties, radiant with energy.