Sound Sculpture / Installation
3.5.m x 0.7.m Security Step Trigger Pads
CD PlayerAmplifier
Speakers
Sheppard-Risset tones are sounds that go up (or down) indefinitely. They are the auditory equivalent to M.C. Escher's famous etching "Ascending and Descending" which depicts an endless staircase. Sheppard-Risset tones are made of a set of partials whose amplitude is bounded by a bell- shaped curve Over time, the frequency of each partial is shifted upward, while its amplitude is adjusted to fit the bell curve. New partials enter the lower end of the bell curve while partials reaching the other end of the curve disappear. As a result, the overall frequency of the sound is constant, but is perceived as going up continuously. Descending sounds are created similarly by shifting the partials downward. |