Let’s Hear if the Painting Hangs Crooked

Psychoacoustic sonification: This term refers to the expression of data in form of sound rather than though visualization. Students at the University of Bremen have now used this technology to create an acoustic spirit level, which is available free of charge in the form of the “Tiltification" App.

“The mobile app for Android and iOS devices equips your phone with a spirit level. For this, it uses the sensors that are built into virtually every smartphone,” explains principle investigator Dr. Tim Ziemer of the university’s Bremen Spatial Cognition Center (BSCC). “For example, you can level a table by simply putting your device on top of it. The highlight: In addition to a visual representation, Tiltification communicates the phone’s angles through sound!”

The app tells you in which direction and how far you have to tilt the phone in order to level it. And it is not using speech – by the time the current angle would be articulated, the angle of the device may have long changed again. Instead, “psychoacoustic sonification” is used. “You might be familiar with a primitive form of sonification from your car’s acoustic parking assistant, which tells you how far off the next obstacle is,” says Ziemer, whose current research topic is psychoacoustic sonification. “This sound can convey significantly more information and is expected, for example, to navigate surgeons through minimally invasive surgeries in the future. Tiltification is now bringing this cutting-edge technology to everyone – in form of a simple but handy app.”

By Laypeople – For Laypeople

In a master’s project at the University of Bremen, students of computer science and digital media had their first encounter with psychoacoustic sonification. Their task: to explain this abstract technology to laypeople in an understandable way and making it accessible. Strictly speaking, psychoacoustic sonification communicates no more than a three-dimensional coordinate. The resolution is hundreds of data points per spatial dimension to dozens of time points per second. How can this technology be visualized; and how can it be of use for everyone – that is what the 20 students asked themselves over the course of a very engaged semester.

The result is available now in the Apple App Store and Google Play in the form of Tiltification, the spirit level mobile application. “The students conceived, developed, and designed this app and actively engaged in social media marketing,” says Ziemer, who is delighted with the remarkable outcome. “Tiltification is a modern form of science communication. For a long time now, multimedia has been an integral part of knowledge transfer. However, an interactive app allows people to not only passively take note of existing technologies, but to experience them first hand, and thus learn to understand them.” The large app stores ensure worldwide availability and easy installation.

Allowing the Unusual Sound

At the same time, the musicologist forewarns users of the initial shock, because the sound is completely unheard of and anything but background music. Nevertheless, users would learn to interpret the sound in just a few minutes like any digital display. And as soon as they can “read” the sound, the startling noise will change for them into an informative sound: “You just have to allow it to happen and not close your ears to it.” Tiltification does not only equips users with a new technology – the app also shows how precisely human hearing can analyze sounds and, in turn, how informative sound can be.

Who Needs an Acoustic Spirit Level?

In addition to anyone who is simply interested in cutting-edge research and new technologies, Tiltification is also for pragmatists:

•   Is the only way to level a table, getting under the table and adjusting its legs with furniture levelers? With the Tiltification app on the table, you can hear which leg still needs a little tweak.
•   Do you have to attach a board above your head all by yourself? Using Tiltification on the board, you can hear when the board is straight.
•   Does a user suffer from a visual impairment? Tiltification makes it audible when something is level.
•   Do you want to take a perfectly horizontal photo? Tiltification helps to align the camera horizontally without any distracting graphics in front of the object.
•   Tiltification can replace the conventional spirit level in many cases, for example for hanging a paint, leveling cupboards, or setting up a caravan.

Tiltification is a simple application of psychoacoustic sonification. You can take a deeper look into this technology by playing the Curat Sonification Game: http://curat.informatik.uni-bremen.de/en/download.html