There's something in the air. An urban hum that simmers at the edge of your attention. Call it ambient noise, or a kind of music-in-waiting. Or you can call it art. From "post-ambient listening lounges" in London's East End galleries to the forthcoming Sonic Boom show at the Hayward Gallery, pretty soon we'll have sound art coming out of our ears.
It's a timely moment, then, for the third annual School of Sound event. A kind of four-day crammer for the aurally-fixated, the School of Sound is the brainchild of sound designer Larry Sider. Coming from film and television, he conceived the event as a symposium to explore the art of sound with the moving image. "This year we have people coming from radio and installation art, not just from film," says Sider, who has chosen the voice as the focus of the event. "The voice is one of those things that sound designers feel left out of. It's not part of the sound design of a film," he explains. "So the idea was twofold: to say that sound design should involve the voice, and that editing and post-production should include sound design."
Sider's belief that sound is routinely devalued in the process of film production, that it's "something tacked on at the end", makes the event more of an agenda-driven intervention than an industry-friendly talking-shop. The eye- and ear-opening eclecticism of its guest speakers has established the School as an annual fixture for those who believe that sound on film can be more than just an exercise in cross-promotion for major record labels.
This year's roster of speakers includes David Toop, composer, writer and curator of Sonic Boom, Manfred Eicher, founder of the German record-label ECM and collaborator with Jean-Luc Godard on his increasing forays into CD releases, and French film sound designer Claude Letessier. Also contributing are the composer Michael Nyman, film theorist Michel Chion, whose seminal study The Voice in Cinema has recently been published in English, and Irish poet Tom Paulin, who'll be talking about "The Despotism of the Eye".
I asked Paulin what he meant by this title. "It's a phrase from Coleridge," he explained. "When you think about how a lot of critics approach poetry, they talk about visual images. But what I noticed about a poet like John Clare is that there's a whole lot of what I call acoustic images - images of sound."
Drawing on the experience of having written a poem for the 50th anniversary of BBC Radio 3, Paulin will be take the experiment further at the School of Sound. "I've done a sound poem that starts with Huckleberry Finn, the voices at night coming across the Mississippi when Huck's in the canoe. It uses bits of other poems with images of sound."
It's not only the intimate quality of the voice, its "grain" if you like, that interests Paulin, but the way speech can be heard as a form of sotto voce subversion. "There's so much stress on presentation in all walks of life. We're living in a managerial, PR culture," he complains "The voice, orality and storytelling militate against that kind of culture."
How's that? "Well, voices are creaturely, aren't they?" he explains with poetic precision. "People who work together spend a lot of time joking and gossiping, if they're lucky. You subvert institutions by talking, don't you?"
Some institutions perhaps, but not, it seems, the institution of cinema. Why, I asked Sider, is it that film, that most hybrid of the arts, should be so backward-looking in comparison to other forms such as radio and installation work. "I think it's because film is now taught as an industry. The film schools are not teaching aesthetics, they're teaching students how to operate Apple Macs," he laments. "The attitude is to get people into the film industry and into TV, and that has separated them from the kind of material we deal with. Having said that, the National Film School is sending 30 students this year, which is the biggest single group of people coming."
No doubt these students will be all ears for Claude Letessier, whose sound design on Terrence Malick's The Thin Red Line is one of the most unusual and unconventional treatments of the voice on film in recent cinema. "Malick wanted it to be a quiet war movie, which is quite peculiar," Letessier recalls of a film whose overall effect is strangely intimate, with the soldiers' voices uniting in choral oneness in the combat zone. "It's a totally unusual approach. It took Malick hundreds of hours to record all the voices and it took the sound-mixer, Andy Nelson, who's English, another hundreds of hours. This movie was made two or three times over to get every fraction in the perfect position."
It was precisely this attention to sound that made The Thin Red Line so different from so much mainstream American fare and a salutary reminder that what a film-maker such as Malick or Lynch or Godard represents is an understanding that the cinematic image is half visual, half sonic.
"I'm interested in those instances in narrative film when speech is overtaken by sound," Toop told me. "I'll be talking about an early Kurosawa film, Stray Dog, where there is a sequence when the sound is replaced by a collage of exotic musics, the Latin music and jazz heard in Japan after the war, which symbolises the character's confusion and his movements through different neighbourhoods."
Toop will also introduce a screening of Hiroshi Teshigahara's 1964 film Woman of the Dunes, which he describes as "really extraordinary, a meditation on texture and eroticism", in a series of associated screenings and talks at the Lux Cinema in Hoxton, east London.
Given his curatorial involvement in Sonic Boom, Toop has clear ideas why sound art should be experiencing a new lease of life. "There are a whole range of people making sound work that, 50 years ago, you would have associated with the avant-garde. Now it's more connected with pop. If you listen to it, it's difficult to say that there's any distinction between what they are doing and what people like Stockhausen were doing in the late Fifties and early Sixties."
Of course, it remains to be seen if the film industry, with its strict demarcation of skills and its hierarchy of image over sound, will draw any liberating examples from the lessons that the other arts provide. But, for four days at least, there will be a chance for interested parties to continue the dialogue that the School of Sound inaugurated three years ago. Maybe its even time to suggest a school motto: free your ears and your mind will follow?
The School of Sound, RIBA, 66 Portland Place, London W1 (020-7323 3437; www.schoolofsound.co.uk) today to Sat. Lux Cinema, 2-4 Hoxton Square, London N1 (020-7684 0200) to 30 Apr. Sonic Boom: The Art of Sound, Hayward Gallery, London SE1 (020-7960 5226) 27 Apr-18 June