Human activity also contributes to background infrasound. Deep below the rumble of city traffic, there is a cacophony of very-low-frequency noise from factories, lorry engines, fireworks, passing aircraft, distant quarrying and many other human sources. In 1957, the French physicist Vladimir Gavreau highlighted this overlooked noise pollution, citing it as a possible cause of city dwellers' stress. (Gavreau, Condat and Saul, 1966)
The installation in lower bay station uses recordings of the subway, which contribute to the "infrasonic zoo" that exists deep below the city. The attendees will hear a composition which uses the sounds of the subway to vibrate objects in lower bay station. This "tactile music" will often be layers of poly-rhythms, due to inspiration from minimalist composers (Steve Reich, etc) as well as African drumming and traditional Shona Mbira music (Zimbabwe). Shona culture views the low frequencies that cause the bottle caps on an Mbira to vibrate sympathetically as a way to talk to spirits. Infrasound is also increasingly being viewed as the cause for ghost sitings.
sound routing :
8 outputs from my laptop correspond to 6 separate tactile transducers in the ceiling, and 2 subwoofer arrays (3 subs either side) in the subway cars.
Each output could be looked at as a part of an eight piece rhythm--take a drum kit as a metaphorical example--the subway cars are the kick drum, the various metal vibrations in the ceiling are the snare, hi hat, toms etc. so the entire station becomes an instrument.
Sounds will be amplified using a combination of :
- subwoofers attached to subway cars, which will turn the subway cars into resonating chambers and create the low resonant vibrations of the metal and plastic train cars.
- Tactile transducers in the ceiling which vibrate pieces of metal that hang down (such as threaded rod with bolts that shake and vibrate). This isn't major earth shattering vibration, but more of a buzzing rhythmic vibration--similar to how bottle caps on the Mbira sympathetically vibrate.
The creation of this installation has been possible due to financial support from :