Ultrasonicmobile is a performance system comprised of three functions:
- capturing ultrasonic information in the sonic environment using a MEMS microphone array designed by Ivano Pelicella of Dodotronic
- transposing the captured ultrasound in realtime to human hearing range using a customized Raspberry Pi micro-controller system designed by Hector Centeno
- broadcasting that transposed signal back into the environment using a directional speaker called the Audio Spotlight
Performances with the system can take the form of a soundwalk where the audience goes on a walk for the purpose of not only listening to the sounds of the environment, but with the intervention of the ultrasonicmobile, to hear the ultrasonic layer that normally is inaudible.
Common household objects such as house keys or video display screens contain ultrasonic information that our bodies absorb physically but that our brains do not process as auditory information. I find that there is a kind of magic that happens when I see and hear the source of a sound in the environment, while at the same time, also hear its ultrasonic transposition in real-time. There is a feeling of mystery and disbelief to this mediated experience, and also an element of unpredictability to it, that makes for a very engaging exploration of sound in the public environment. There is also a musical richness to this ultrasonic material that begs further exploration and experimentation.
As an interesting comparison, here is a recording of a soundscape in my home in South River, Ontario, Canada.
The left channel of the soundscape is recorded with the MEMS ultrasonic array at 96 khz sampling rate with no transposition and the right channel is recorded with the same microphone but transposed in real-time using the software/hardware designed by Hector Centeno. This example provides a sense of the layer of ultrasonic material that goes unnoticed by humans when listening to the soundscape.
Ultrasonicmobile is available for outdoor performances, soundwalks and public art performance interventions.
Financial support for the creation and research of Ultrasonicmobile was made possible through support from the Canada Council for the Arts.
- Ultrasonicmobile Recording System. Photo by Hector Centeno.
- Darren Copeland Performing with Audio Spotlight. Photos by Stefan Rose.
- Andreas Kahre performing for a soundwalk in Victoria Park in Kitchener for CAFKA 2014. Photos by Stefan Rose
- Ultrasonic soundscape recording made by Darren Copeland.