Natural Science Exhibition, 2011
Copenhagen Zoo, Denmark

Sound: Steven Gelineck, Production: Kamilla Thomson, Direction: Rama Hoetzlein

The EcoPlayer is an interactive exhibit which invites children to learn and play with animal sounds, while older children learn about computer vision and image processing. Scientists are interested in transforming natural sounds in order to understand them better. The EcoPlayer, or Ecological Audio Environment, is a multimedia device for experimenting with sound. In this exhibition, users move blocks to modify location, pitch, tonality, and range, which allows one to explore changes in sounds made by animals. Modern computer vision is used to track the positions of the blocks on the table, which then change features in the sound.

Video of the exhibit shows children interacting with the system. Animal pucks represent distinct animal sounds, including a parrot, lion, monkey, cat, and elephant. Placing the puck on the table alone produces the sound of that animal. Filter pucks allow the user to explore modifications to the sound, including pitch changes, echoing effects, and FM synthesis. Combinations of animals and filters produce a unique variety of sounds.

The EcoPlayer exists on two sides of a dividing wall. The left side of the exhibit, intended for younger children, includes the EcoPlayer table and the pucks for sound synthesis and manipulation. Fiducial markers are used for tracking the pucks using a 100 fps camera.

The right side of the exhibit, intended for older children, shows the computer tracking in progress, and two windows to see person moving the pucks and the inside of the EcoPlayer device itself. A description explains the tracking process. Exposing the operation of the device in this way allows children to understand the system of multiple levels. In practice, children would often use the window to communicate goals between the two sides (See video above).
Exhibited at the Copenhagen Zoo for education week at the Nature Science Festival, detailed posters were created for each side to describe the project to children and participants. The sound poster exlains the process of sound localization, and how it is used in the project. Posters include both Danish and English translations.
The vision poster describes the similarities between human vision and computer vision, from sight to signal to semantic recognition. The system uses fiducial markers to identify position and orientation of the eight pucks, which are then used to drive sound synthesis occuring in Max/MSP.