The Very Large Array - FAQ

• Q. What are those things on the ends of the VLA modules?
  A. Those are speakers. Each VLA module emits a monophonic sound - due to circuit exigencies, using two speakers turned out to be convenient.

• Q. Is that little black thing on top of the VLA module a button?
  A. No, it's a light sensor. Please don't press on it!

• Q. Is the VLA solar powered?
  A. No. Each VLA module has its own battery, which stores enough power for about 5 nights of operation.

• Q. I visited the VLA during the daytime, and it wasn't working. What's wrong with it?
  A. The VLA is quiet during the day, and makes sound at night.

• Q. Are the VLA modules connected?
  A. No. The modules of the VLA are completely independent.

• Q. How does it work?
  A. The VLA is based on a sound record/playback integrated circuit created by Information Storage Devices. This integrated circuit is like a tape recorder on a chip. In addition, each VLA module contains an IR phototransistor for light detection, a battery, two speakers, some random passive components, and a simple microcontroller made by Microchip Technology Inc.

• Q. Are all the sounds different?
  A. The sounds are all different, but many similarities exist. I find that using subtle differences between adjacent modules leads to the most pleasing effect.

• Q. Where do the sounds come from? How are they arranged?
  A. Several arrangements of sound have been used:
  • Nov. 2, 1997 and before: various sounds of natural origin were used to create a collage. Cosmic background noise, radio noise from various celestial bodies, bird song, the whooping of gibbons, insect sounds and dripping water all found a voice. The square grid of modules was structured as concentric squares, with a tendency to have noisier, more random sounds in the outer layers, and more musical sounds in the inner layers.
  • July 4, 1998 on Black Rock: 16 distinct but similar sounds were created using the fmvoice instrument in the fine software synthesis program, Csound, v 3.477. See here for more info on Csound.
  • Burning Man 1998: using the experience gained on July 4, I created a much more complex set of sounds using Csound. The VLA was arranged as 4 outer 4x4 grids around an inner 6x6 grid. Each 4x4 grid had a distinct theme, with subtle variation among modules; the 6x6 inner grid contained Csound-synthesized sounds, as well as a collage of sounds taken from a recording made for me at Davenport Beach on Oct. 5, 1997.

• Q. When will the VLA make its next appearance?
  A. I have no current plans to set the VLA up again. The difficulty of finding a proper location, the sheer work involved, and my disgruntlement at the theft of 4 VLA modules at Burning Man 1998 argue against it. Maybe on Black Rock in 2000!