In the installation Pneumatic Sound Field a continuum is being created between rhythmical perception of sound, spatial perception of sound and the perception of pitch. A horizontal plane of pneumatic valves is used to produce wind, pressure and sound. The result is a breathing sound environment above the audience.
Acoustical sound consists of temporary pressure changes traveling through the atmosphere of the air around us. While loudspeakers most often use moving membranes in order to produce these pressure changes in Pneumatic Sound Field compressed air is being used to produce acoustical sound. The compressed air is connected to very fast controllable pneumatic valves that release the pressurized air in the 'open' air. This results in a controllable pressure change in the atmosphere around the valve. Because the compressed air has always a higher pressure than the atmosphere not only sound is being produced but also a bit of wind. The result can be seen as wind that contains sound.
Our hearing has just as our seeing a change in perception around the frequency range of 16 to 20 Hertz. A sequence of film frames is being perceived by us as something happening in time in stead of individual frames with jumps in between when the frame rate is higher than about 16 frames per second. The same counts for our hearing. Repeating vibrations with a repetition frequency higher than 16 Hz are being perceived as tones while at a lower repetition frequency they are being perceived as individual pulses.
The spatial perception of the location of a sound source is partly determined by the difference in arrival time of the source at the left ear and the source at the right ear. This technique is often reversely applied in stereo reproduction where a mono sound is played little earlier out of the left speaker then the right speaker (or reversely) in order to spatialize the sound at any location between the two loudspeakers.
Pneumatic Sound Field uses spatial time delays of impulses over the 42 valves. By using different speeds, delays and repetitions a continuum is being created between the spatial rhythmical patterns, spatial localization of sound, movement of sound and the perception of tones and pitches.
Live binaural microphone recording made during the exhibition at the Donaueschinger Musiktage, Donaueschingen, Germany, 2012. The recording contains one of the three parts that were presented. The recording is meant to be listened to on (high quality) headphones. Duration: 6 minutes and 22 seconds. © Edwin van der Heide