Minoru Sato - Detecting space conditions from phase-contrast by using sine waves and a gate on various sounds
  Year :   1996
  Location :   Japan
  Worktype :   performance
  Materials:   -
  Info :   uplink factory

  Work Details  
  Sound, from the point of physics, as a wave/vibration phenomenon, propagates in any space where medium (matter) exists. In the propagation process, for example, in a space with elements (such as; walls, a floor, a ceiling and so on), some reflection and diffraction of the sound will arise. These effects appear as a phase-contrast and are, of course, observable in the space. The phase-contrast is generated by 1) the difference in the distances between a direct course from the sound source and several courses via reflection and diffraction, 2) the phase change which depends on any fluctuation of boundary conditions of the elements when the reflection or diffraction arises. The contrast mostly appears as any fluctuation of amplitude (changes in the loudness of the sound). Even the loudness of a sine wave from an oscillator changes with any motion of the elements. For this reason, observing the phase-contrast at a fixed location becomes an index to dynamically measure the conditions of a space. In this work, the volumes of the sine waves (from the oscillators) are fixed and played in the performance space. At the same time, the sound waves in the space are recorded at a particular location in the space. Later on, the recorded sound is played back through a custom-made gate modulator. When the amplitude of the sound passes through a particular gate level, only parts of the recorded sound can pass through the gate. If we hypothesize that the elements have no movement, then the recorded sound becomes a fixed amplitude. If so, it is either possible or impossible for the sound to pass through as a whole. When the space condition changes (some movement of the elements, as well as, the movement of observers/audience), the change effects the phase-contrast. In a way, when the change is comparable to the motion of the sine wave from the oscillators, some fluctuation also affects the recorded sound. What we can find, in this way of detection of the condition of a space, is that it might make clearer, how we are concerned with a space and its components (elements, such as walls, etc), each as a function and an activity of the conditions of a space. Finally, in the result, we can hear the whole activity of a given space. (text by m/s)