Sonification of a Toilet System
The data for this sonification originate in a R&D project concerned with the development of a toilet system that meets the needs of older people and those with (physical) disabilities. In the final stage of the project, a prototype was installed at a day centre for patients with multiple sclerosis in Vienna. There, the system was tested in a setting as close to real life as possible. For ethical reasons, direct observation of the user’s interaction with the toilet system was impossible. Thus, the sole data source showing the interaction of users with the equipment in this final stage was log files that were continuously produced by a computer mounted near the toilet. This computer logged the status of several sensors on the adjustable toilet prototype: the height and tilt of the toilet seat were registered, as well as the status of the six buttons on a remote control (tilt up/down, height up/down, flush, alarm), and other more technical measures.
A standard graphical display did not allow for a clear or intuitive representation of time sequences, especially when dealing with a huge number of data files. As the computer logged about two hundred and forty hours in total at a resolution of a tenth of a second, a file containing a single hour’s data comprised about thirty-six thousand cases. Superficial screening of a data-set with these dimensions is hardly possible with a graphical display. Note that graph 1 displays only about ten minutes - if one wishes to display the whole data material graphically, one needed to produce 1440 graphs like it. The sonification technique chosen in this case was parameter mapping. A specific sound event was assigned to each variable of interest. In total, we ended up with nine variables plus time as the basic dimension.
With the given data, the human ear is capable of tracking the sequence of events even when accelerated by a factor of a hundred – in other words one is able to perceive a sequential order spread over a hundred seconds even when it is compressed into one second.
Further, sonification provides a more dynamic representation of the events’ sequential order. The intrinsic time factor of the auditory representation helps the researcher to comprehend the sequential order much better than the standard, static graphical displays. It reproduces a temporal phenomenon in its natural dimension, time, not in space, as the static graph does. While dynamic graphical displays would also offer time-to-time representation, following several parameters and their timing patterns visually is much more difficult.
The sound example represents the same sequences of events as displayed in the graph. Height and tilt of the toilet are represented by continuous sounds that become louder when there are changes in the data. The pressing of the buttons of the remote control is indicated by different single, bell-like sounds. The flush and the status of the door are represented by distinct kinds of noise.
- Dayé, Christian & Alberto de Campo (2006): "Sounds sequential: sonification in the social sciences." Interdisciplinary Science Reviews 31/4. 349-364.
- Dayé, Christian, Christian Fleck, Alberto de Campo et al. (2005): "Sonification as a tool to reconstruct users' actions in unobservable areas." Proceedings of the 11th International Conference on Auditory Display, Limerick, Ireland, July 6-9, 2005. 328-331.