"It's a software mechanism for telling the hardware what to do," says Morris. He explains that once a person has mapped different functions onto the controller, she's able to save it for later or pass it along to someone else who has a similar role in the editing process.

The paper, presented at CHI 2009 by Rebecca Fiebrink, a graduate student at Princeton University, also describes a study examining how people used the interface. Most of the study participants used the physical controls, favoring the accuracy and responsiveness that they offer. However, these participants also made extensive use of surface controls, choosing them mainly for tasks in which a single touch produced a discrete result, such as playing or stopping a track.

Robert Jacob, a professor of electrical engineering at Tufts University, in Medford, MA, says that the researchers "did a nice job of investigating what users actually did when given both [physical controllers and a touch screen] and the opportunity to switch between them."

Jacob, who chaired the session in which the paper was presented, acknowledges that bridging the gap between physical and digital objects can be challenging. "It's a difficult problem with no general solutions, but rather individual interesting designs," he says. "Ideally, you want the benefits of the digital without giving up those of the physical."

While Ensemble was designed for sound editing, its underlying technology could find other applications in graphics, gaming, and visual design, says Morris. "It could be used in scenarios where you want people to collaborate on a surface as a group," he says, but where the resolution of touch surface limits the precision of the virtual controls.