Source Code. Projects. Nerd Stuff. Art Stuff.

Echos of Footsteps

Posted on January 13th, by amoeboar in classes, cookingwithsound. No Comments

[gn_media url="" width="600" height="400"]

Made in collaboration with Louise Foo, Echoes of Footprints is an interactive sonic installation that uses echolocation to manipulate sound. The concept page for this project can be found in an earlier blog post.


For the prototype, the ultrasonic sensor array was placed at the height of a person’s elbows, so that we could make quick changes. We later decided to move the sensor array down to the foot level, because we didn’t like how our testers waves their hands in front of the sensors. We wanted to create more of an atmosphere, whereby the sounds could be created through natural movement, or inadvertently to the unknowing passerby.

Each sensor emits a pulse, and listens for an echo. It measures distance by counting the time taken for a wave to be emitted, reflect off an object, and return. This is called echolocation, and is the same way bats can determine where a cave’s walls are and how dolphins and whales navigate and communicate underwater. We settled on the name “Echos of Footprints” because the changing soundscape becomes a representation of the viewers temporary footprints in the space.




(Thanks to Louise Foo for the images)

echos_maxpat Max Patch for sending note and control values to Ableton. Takes serial data from Arduino, groups it according to channel, adds some smoothing, and converts the signal to MIDI.

echos_ableton Ableton set, primarily composed of dolphin and whale noises!

Samples collected from scientific ocean recordings made with underwater hydrophones that detect acoustic signals in the ocean.

Sound Sources:
NOAA (National Ocieanic and Atmospheric Administration), DolphinEar, Whalewatch, Discovery Channel, Wired, National Geographic.

Leave a Reply