I am often asked questions about how the use of digital technology and networks affects my work with soundscapes.

I began creating acoustic networks of sounds as the aesthetic basis of my work in the mid 1970's. At this time, digital technology did not exist. These analog networks were guided by aesthetic ideas about the inherent musicality of sound in the environment.

It was, and still is my belief that the world at any given moment contains unimaginable acoustic complexity. My methodology has been to express this wide horizon of possibilities as a spatial grid of simultaneous listening points that relay real time acoustic data to a common listening zone. Since 1976, I have called such musical information strategies, sound sculptures.

The earliest works were temporary networks realized with mobile 8 channel recorders. Kirribilli Wharf (Sydney, 1976) was the first successful work in the genre, and marked a turning point. In the middle of the night, I went with an outside broadcast van to a floating concrete pier in Sydney Harbor that had vertical cylindrical holes going from the deck to the underside. The movement of waves would close the bottom ends of these holes creating compressions waves. These were audible by means of microphones placed in the openings of these holes (8 were used). The recording that ensued revealed a highly musical wave map defined by the changing percussive rhythms of the simultaneously miked blowholes. This array of microphones was a musical information network that revealed a complex result not discernable from any individual point taken separately.

From mobile 8 channel recordings that sampled 30 to 60 minutes of real time in the life of an acoustic situation, it was a easy to make the leap to using analog (broadcast quality) telephone lines and wireless communication to investigate the simultaneity of sound in a much wider acoustic situation called a landscape. These installations covered greater distances and time scales that further expanded the conceptual envelope of connecting multiple spatial points to a single defined listening zone that used multiple loudspeakers to render to the acoustic topography of a landscape.

The earliest examples of these were in Melbourne, Australia in 1978, where sounds were transmitted by telephone line and wireless transmitters to the National Gallery of Victoria in a series of installations ­Sound Sculpture Resonators, Moorabin Airport and Sound Sculpture with a Sequence of Level Crossings.

From 1979 to 1992 I produced a large number of installations in the U.S., Europe, Australia and Japan that explored and developed the idea of creating musical information networks. These all used the analog transmission technologies of the time, and had the general structural form of connecting multiple points to a single zone. What was significant in this process was the conceptual links that determined the selection of microphone transmission points and site-specific qualities of the listening zones.

In LANDSCAPE SCULPTURE WITH FOG HORNS (San Francisco, 1981) loudspeakers were mounted along the facade of a long pier building in San Francisco Bay, playing a live 8 channel sound map of the echo/delay patterns of fog horns. This listening / receiving zone functioned as a 9th location in the real time sound map, as it was part of the natural sound field of the fog horns. This created a sophisticated degree of acoustic interactions between the transmitted sounds and the ambiance of the pier. The method of transmission was 15 kHz telephone lines.

In 1983 the Brooklyn Bridge was 100 years old, and I created my most ambitious acoustic network to date by relaying the live singing sounds of the steel grid roadway of the Bridge to four locations simultaneously: the facade of 1 World Trade Center, the observation Terrace of 1 World Trade Center, the Brooklyn Museum and the public radio station in New York, WNYC. Transmission method here was 15 kHz telephone lines.

In 1987 I realized the largest analog acoustic network of the time, the Cologne San Francisco Sound Bridge. In that project, there were installations existing in both Cologne and San Francisco that for one hour were linked by satellite and played all over Europe, the USA and Canada on radio. The Cologne installation was a live sound portrait of the city, with microphones at 16 locations in Cologne, with loudspeakers on the facade of the Cologne Cathedra and other rooftops surrounding Roncalliplatz. The San Francisco installation was a live duet between the Golden Gate Bridge and the Farallon Islands National Wildlife Refuge (which lies 30 nautical miles west of the Bridge) ­this was heard at SFMOMA.

In 1990 two large analog projects were realized, LANDSCAPE SOUNDINGS in Vienna and ACOUSTICAL VIEWS OF KYOTO. The Vienna project was installed in large public space, the Maria Theresean Platz situated between the Kunsthistorisches and Naturhistorisches Museums. Sixteen microphones placed in an ancient wetland of the Danube, the Hainburger Au, transmitted via a multiplexer over a microwave link. This was also broadcast many times by the ORF. In the Kyoto project, a receiving zone that had panoramic views of Kyoto took live sounds from different parts of the city, so that visitors could hear as far as they see.

If digital networks had existed when any of these projects were realized it would not have changed the immediate experience at the receiving zones, except to have had much better sound quality.
The other interesting dimension that did not exist, but by today's standards would have been interesting would have been to create web versions of these projects, where people could navigate the many individual sound source locations, and generate their own mixes of the material.

A very recent project, TIDAL WAVES (Kingston Upon Hull, UK ­2002) is an example an acoustic network that uses the simplest analog technology to achieve a sophisticated result. Hull is located on the estuary of the Humber river and North Sea. It has extreme tidal variations of 12 to 15 meters. There is an old jetty on the Humber (see photo) that is no longer used, that is a four story steel structure. During a high tide 3 of the four levels are submerged. I used this situation to create an acoustic tide gauge in which disk shaped hydrophones are mounted on each of the three levels (see photo). During a high tide, when they are completely submerged, one hears the water moving through the structure. During a low tide, when none of these are submerged, the hydrophones become accelerometers and hear interior structural sounds of the jetty.
As the tides come ebb and flow, this musical network is slowly changing between these two acoustic polarities. Something that is remarkable in Hull, is that the town has its own telephone company. In order to achieve the transmission of this situation to the Maritime Museum, the phone company installed 4 twisted pairs of copper wire, point to point, with no signal conditioning equipment. With the help of a good engineer, we installed 12 to 1 transformers at each end of the line, and had a very high quality analog signal.

In terms of the future of my work, the basic personal aesthetic of creating a musical information network from multiple sound locations in the environment is still a valid way to work. The digital enhancements to this will be multiple receiving sites, an interactive web presence for the works and the possibility to have interactive relationships between transmission and receiving sites.