two contact microphones, two tactile speakers on sheet metal, two monitor speakers, mixer, modular effects, transporter

Two contact microphones are placed at different locations of a bridge. They pick up the bending and transversal wave components of the structure borne sound inside the bridge solid body. The waves inside the bridge are excited through cars rolling over the threshold of the bridge suspension. Tactile speakers on sheet metal and two monitor speakers broadcast the sound inside a transporter, parked closeby. As structure borne sound has a frequency dependent propagation speed, the short impulse punches given by the cars are blurred to a stretched hissing sound picked up from the bridge column. A second recording position on a tube attached to the bridge has characteristics of a resonator, emphasizing certain frequencies in the spectrum. The events made audible in the resulting soundscape are determined by the sequence cars pass the bridge. Variations therefore appear on different timescales: Over the eight hour course of the installation the number of cars varies depending on the time of the day. Traffic lights additionally modulate the event density repeatedly over the course of few minutes. The particular distance between the cars and the resulting time between two sounds is always different and the quality varies depending on the weight of the vehicle. Occasional interventions with a modular synthesizer experimenting with the live input from the bridge add layers of aesthetic conversation.
Contemplating the otherwise inaudible sound inside the bridge structure questions how we audibly perceive the urban environment. Sounds in cities are often unwanted and perceived as noise pollution, apprehensibly rejected through headphones, walls or annoyance. This is dismissing the ability of sound to constitute a shared and pleasant urban space. Paying attention to our surroundings and being able to perceive its often subtle qualities can be a departing point to rediscuss how we want to shape the cities we live in.