Background Activity is unconstrained movement of body parts and vocalizations, which is under-represented in most canonical data sets of human behaviour used for designing or evaluating Gestural Interaction.
The Background Activity Project is described in full in the paper
A Dataset of Naturally Occurring, Whole-Body Background Activity to Reduce Gesture Conflicts
http://arxiv.org/abs/1509.06109
From this page, you may request access to the wealth of data collected as part of the Background Activity Project.
Code for reading data associated with the project is available on GitHub.
For more information, please email: dustin [AT SIGN] cs.toronto [DOT] edu