I am in a nuclear bunker watching four men in suits and ties coax warped electronic sounds from children's toys, including a Texas Instruments Speak & Spell and a Barbie doll with red, glowing eyes. This is the Modified Toy Orchestra, led by the sound artist Brian Duffy, who rearranges the circuitry of discarded playthings to make them do things for which they were never intended. The performance is part of Faster Than Sound, the second annual evening of sound art and experimental music to take place at the disused Bentwaters airbase in Suffolk. This event is the most out-there element of the predominantly classical Aldeburgh Festival.
Once home to the US air force and reportedly a terrifying quantity of nuclear weaponry, Bentwaters these days is, rather less impressively, the location for the filming of BBC3's pet obedience show Dog Borstal. Nevertheless, the looming warehouses, glowing watchtowers and reports of UFO sightings in 1980 make the location terrifically spooky, even without all the distorted electronic pulses now floating through the air.
Sound art is a fast-growing field, and many of these performers demonstrate its pleasures. I sit in the middle of a circle of huge speakers, mesmerised by the hypnotic sound of Iceland's Hildur Guðnadóttir, who plays a cello and layers the sound into endless refracting loops with a laptop. I walk through the darkening woods with wireless headphones, listening to a recording of American pilots describing their pos sible UFO while the bushes glow with eerie lighting, and almost believe it. Mark Limbrick's 1 is great fun - two coiled speakers joined by a ten-metre wire, the grown-up equivalent of a child's two yoghurt pots and a piece of string. People line up to twang, scrape and bash it, making an array of fascinating, boinging noises.
Others are less successful. Anticipation by Mike Challis features all the sounds normally cut out of a concert recording at Aldeburgh - that is, all the applauding and tuning - but no music. It's a neat idea, but the concept far outweighs any satisfaction to be had from the experience of listening. Sonumbra by Loop.pH, a kind of glowing rotary washing line making soothing sounds, is like a lot of sonic art: it is apparently interactive, but it remains unclear what effect the listener actually has on the noises that it produces.
However, Faster Than Sound achieves its desired effect, opening the ears to noises far beyond the boundaries of what normally constitutes music. In my job as a pop critic, I am unused to listening out for more than a funky rhythm, snappy lyric and decent tune. Soon, even the sounds of the birds in the trees and the hissing of the burger van begin to take on a weighty, unspecified significance.
Joana Seguro, the event's programmer, marks the distinction between sound art and music as one of freedom. "With traditional music, you're restricted to the frequencies and range of your instrument," she explains. "When you're playing with technology, you don't have those boundaries, so someone who doesn't have a background as a musician can still make sound art."
Fittingly, one of the original proponents of sound art was a painter, the Italian futurist Luigi Russolo. He wrote the manifesto The Art of Noises in 1913, suggesting that trams, cars and crowds could also be music. The idea gained most notoriety with the arrival in 1952 of John Cage's 4'33" - a period of silence from a pianist during which any noise from the hall or audience becomes the composition.
Now sound art is experiencing a renaissance in Britain. This month, following Faster Than Sound, the exhibition "Soundwaves" takes place at the Kinetica Museum in Spitalfields Market, London, and the annual Expo festival of sound art visits Plymouth. In February this year, five separate new music and sonic art organisations were awarded a joint grant of almost £1.2m in total by Arts Council England, becoming one body under the working title the New Organisation, and thereby increasing their profile considerably.
It helps that technology has finally caught up with the imagination of the artist - it is possible today to do almost anything with sound, using equipment no bigger and no more complicated than a laptop. Accordingly, levels of ambition are high. The composer Dan Jones, who has worked with the Sound and Fury theatre company on plays that take place in total darkness, revives Sky Orchestra, his magical, spectacular collaboration with the visual artist Luke Jerram, in the Midlands in September. The City of Birmingham Symphony Orchestra will play his music from six hot-air balloons floating over Birmingham at dawn, hoping to influence the dreams of people below. Before then, between 21 June and 3 July, the pair are presenting a new sound and light installation in a 300-metre-long Post Office tunnel beneath the same city.
"Sound is a particularly interesting way to play with people's perceptions," says Jones. "Most of the time we're not consciously aware of what we're hearing - there's hardly a moment on television when music isn't playing, for example - so placing the focus directly on that sense can be very disorientating."
It seems strange that, in a world where we never truly experience silence, being asked to listen can be such a powerful sensation. Music has become as readily available as tap water, freely shared on the internet, blaring out in every public space and from every passing car. When sound art succeeds, it reminds us how precious our sense of hearing really is.
"Soundwaves" runs at Old Spitalfields Market, London E1, until 29 June. http://www.cybersonica.org
"Expo" takes place in Plymouth from 22-25 June. http://www.sonicartsnetwork.org