When Brian Eno issued his manifesto of ambient music in the liner notes to his 1979 album Music for Airports (EG), he couldn’t have known the extent to which his ideas and his work would one day be reflected in popular music. By arguing for the creation of synthetic textures that would not only " induce calm and a space to think, " but " tint " or " perfume " the environment in which they unfolded, the former Roxy Music keyboardist anticipated the minimalist trend in electronica exemplified today by Aphex Twin, Pan Sonic, and even, to a degree, DJ Spooky. Glitch, dark ambient, illbient, ambient dub, and trip-hop are all offshoots, in spirit if not substance, of Eno’s Another Green World (Island, 1975). But his attempt to approximate visual art’s environmental impact using sound may have found its purest expression in the impressionistic work of a Somerville-based duo recording under the name United States of Belt.

" Pure " is a loaded word, but it’s fitting in the case of recording artists who have abandoned instruments, including synths and samplers, altogether. Seth Barger and Ross Goldstein, the two masterminds behind United States of Belt, have a passion for transforming the noisy universe around us into soundscapes of subtle beauty and great imagination. On their first CD, 1999’s Sparkle Night, Mojave, which they issued on their own Champ label, USOB made extensive field recordings of natural environments that were later fused into a majestic time capsule of what you could call elected occurrences. Armed with a few studio mikes, a DAT machine, and some homemade windscreens, the pair gathered most of their found sounds on a cross-country road trip. Then they spent months editing the tapes into a 44-minute sonic collage.

Starkly quiet and dreamlike, Sparkle Night has a lost-highway feel in the way it evokes a night in the life of a desolate place. Chance events captured in real time — a passing train, carnival music, blustery winds, a crowing cock — overlap on the disc, giving a hallucinatory quality to the rich atmosphere of silence and spaciousness. As an experiment in acoustic mood enhancement, Sparkle Night also satisfies Eno’s dictum that ambient music must be as ignorable as it is interesting, capable of accommodating different listener levels of attention.

Goldstein and Barger are aware that in moments of drift Sparkle Night blends with the natural ambiance of sounds floating through an open window. But they say that’s part of the album’s essential organicism. " I think our work has a lot to do with going out into the world, " Goldstein explains. " It’s more about collaging and overlapping experiences that we’ve had and reliving that through listening to them than creating a musical composition. How it gets put together is really what it’s about. "

The idea for the Sparkle project came together in 1998, after Barger, a performance artist with a master’s degree from the Museum School, collaborated with Goldstein on a soundtrack for one of his pieces. He agrees that the editing process is crucial to giving their aural sculptures an artistic value. " I just see it as trying to create places using sound as a material — trying to create environments or stir emotion or mood or whatever each composition calls for. But it’s the material aspect that’s so different, since we’re not taking the sound of a doorway opening and then looping it and turning it into a rhythmic thing. "

When they set out to record the source material for their new mini-CD, Cyclones (Champ), United States of Belt knew they wanted to explore the cultural significance of the Coney Island amusement park, and they decided to take movement as a central theme. Aiming for a more visceral feel than on Sparkle Night, Goldstein and Barger tried to re-create the physical vibrations of that fairground’s premier roller-coaster, the Cyclone. At regular intervals on the disc, you hear the familiar sound of rickety cars on their way up the steep incline, as well as the exhilarating swoosh of air and the rattle of old wood and metal as the falling coaster carves a bend in the track. It’s a perfect cipher for nostalgia, drawn from the bank of sensory images collectively held by anyone who’s ever screamed his or her head off at an amusement park.

But there’s more to Cyclones than coasters and cotton-candy salesmen. Calling it " an exploration of cyclical forms, " Goldstein says the 13-minute CD is " an attempt to create an imaginary reality in real time. " That sense of otherworldliness comes through in the intricate weave of incongruous sounds, and the way they’ve compressed past experiences and lived memories into a maplike whole. " Time kind of gets twisted, " Barger adds. " When you look at the cover, there’s a picture of a watertower. People don’t believe that’s a real place. That’s another extension of the work. When they listen to it, they might think, ‘Oh, I’ve had that experience before, I’ve been to that place,’ but it’s actually four different places playing off each other and creating that feeling. " That idea of being-present-nowhere-in-particular suits the work, especially when you consider that the sounds were gathered in such disparate locations as Texas, New Mexico, Memphis, Clarksdale, Central Park, and the banks of the Mississippi and Charles Rivers.

Although Goldstein and Barger have no interest in adding electronic frills or effects to their soundscapes, they aren’t wedded to acoustic purity for its own sake. " A train sound can give you a feeling of movement, steel, weight, power, " Goldstein says. " It can also just sound cool and give you a texture. " But they do have a few tricks up their sleeves. Instead of using a conventional reverb box, for instance, they took a portable playback device into the cavernous interior of the Boston Cyclorama, projected sounds, and re-recorded the echoey results. And in their one concession to electronic manipulation, they used a pitch sequencer on Sparkle Night to tune the desert wind and a lone rabbit whistle to E-flat. The point was to create a low-volume drone that would anchor the piece, giving it a narrative as well as a vaguely musical flow.

Although they cite as influences pioneers like John Cage, Eno, and even Harry Smith, who made hundreds of cassettes of environmental sounds (in addition to his now-famous anthology of folk recordings), apparently looking for patterns that repeated themselves, both members of USOB express some doubt as to whether what they are doing can be called music. Explaining that visual artists have been just as inspiring, Goldstein shows me a reproduction of David Hockney’s Yellow Chair with Shadow, a Polaroid mosaic the artist dubbed a " joiner, " to illustrate his point.

As for the fledgling Champ label, Goldstein and Barger say they are looking for local experimental artists to sign. For now, though, they are focusing on putting out United States of Belt recordings and promoting the new CD. Anomalous Records, an on-line distributor, has been helping them get copies into the hands of abstract-music lovers, and Harvard Square’s ultra-selective Other Music has been generous too, adding Sparkle Night to its display rack. USOB are also working hard on champrecords.com, a sophisticated Web site that features samples from Cyclones and a few bizarre photo collages of industrial landscapes.

So how will their " pure ambient " sound sculptures fare in the long run? " Our work in time will represent what the environment sounded like, " Goldstein says, " the way cash registers don’t ring the same anymore and car horns change over time. I think it’s made for the future. "