Changing Signals is an audio-visual piece commissioned in August 2013 by GV Art Gallery London for the exhibition Noise and Whispers. The piece explores the hidden sounds of the London Tube and train network. These unheard sounds are produced electromagnetically by trains and equipment and are recorded through custom-built inductor devices. These devices are formed of large coils of wire and convert Very Low Frequency (VLF) electromagnetic radio, a frequency band of the electromagnetic spectrum, into sound and other data. VLF has scientific applications in the fields of radio astronomy and seismography. The recordings expose a sound world that is experienced everyday but never heard by the many passengers of the London train network.
The audio is accompanied by footage of the objects, which generate these sounds set alongside images and film of the scientific apparatus used to record and analyze electromagnetic and VLF data such as oscilloscopes, spectrograms and seismographs.
Changing Signals has additionally been presented: Turbulent Forms, Factory Media Centre, Hamilton, Canada, 2016, Seeing Sound Conference, Bath Spa University, 2016