On the occasion of the 25th anniversary of the festival Randspiele in Zepernick (near Berlin) in 2017 this installation was projecting sounds from the past 24 years into the churchyard of the Sankt Annen Kirche.
sound examples (on-site recording):
In acoustics the reverberation time is the time it takes for the sound pressure in a room to drop by a factor of a thousandth compared to the value before the sound source became silent.
But in reality the reverberation does not suddenly stop at -60 dB. The sound goes on, softer and softer, until it can't be anymore perceived by the ear or by the microphone, until it get lost in the background noise. Or does it actually become part of the background noise? And if the sounds aren't really completely vanished but altogether continue to exist as noise - why shouldn't it be possible to revert this process for certain sounds?
The recently developed hexa-sonal Residual-Sound-Magnifier allows the resonification of seemingly decayed sound signals at a place by focussing on a temporal sediment of the surrounding noise. Depending on the temporal distance one can isolate only short fragments from the noise. By means of Wavelet-Matching – an acoustic jigsaw puzzle – these fossil sound fragments must be assembled together.
Unfortunately the original sounds can't be always reliably reconstructed by this method. Thus we only get some vague information about pitches from the beginnings of the Randspiele festival, but the actual sounds of the early years are lost indeed...