Edgar Berdahl - eberdahl@mail.tu-berlin.de
Audio Communication Group
Technical University of Berlin
Sekretariat EN-8
Einsteinufer 17c
10587 Berlin
Germany
Popular version of paper 4aMUa7
Presented Thursday morning, Nov 03, 2011
162nd ASA Meeting, San Diego, Calif.
The FireSlider (see representation in Fig. 1) includes a fader, similar to those found in a mixing console, but it is not just a volume control! The FireSlider enables a human user to interact mechanically with digital sound. The sound and the motion of the user's hand are connected in feedback: the motion of the user's hand affects the sound, and the sound also causes the user's hand to move in response. This feedback is made possible by a small motor hidden within the housing that pushes on the fader. The feedback loop causes the motion and the digital sound to be correlated. Additional lamps are connected to the same circuit as the motor in order to produce a high-frequency visual signal that is also correlated with the force, enabling observers to immediately infer the motor force even at a distance.
This particular work addresses the question of reducing the cost of force-feedback devices for applications with sound. For example, the FireSlider itself does not contain a powerful computer. Instead, a standard USB cable connects it to a common laptop computer (not shown), which carries out the computations necessary for the FireSlider. Multiple, relatively inexpensive sensors are employed. For example, besides the fader potentiometer that measures the position of the fader, force-sensitive resistors measure the downward pressure applied by the human to the fader.
The FireSlider can be programmed to implement many different interactions, both physical and non-physical. For example, with the help of a computer program that emulates the acoustics of a fictitious musical instrument, more commonly known as a "physical model," a user can play the fictitious instrument in real time, while the user hears and even *feels* the instrument via the computed force feedback. Alternatively, as shown in Berdahl's doctoral dissertation, non-physical and almost "imaginary" interactions can be implemented, enabling a musician to perform gestures that would otherwise be difficult or impossible, such as superhumanly fast drum rolls. While the wealth of programmable interactions is astounding, the focus of the FireSlider project is on the creation of digital interactions that are immersive, expressive, intuitive, and exciting.
References:
E. Berdahl, Applications of feedback control to musical instrument design, Ph.D. dissertation, Stanford University, Stanford, CA, 2010 (available online: http://ccrma.stanford.edu/eberdahl/berdahl-thesis.pdf (date last viewed 6/13/10)).
E. Berdahl, C. Cadoz, J.-L. Florens. Using Physical Models is Necessary to Guarantee Stabile Analog Haptic Feedback for Any User and Haptic Device. in Proceedings of the Eighth Sound and Music Computing Conference, Padova, Italy, July 6-9 2011.
C. Cadoz, A. Luciani, and J.-L. Florens. CORDIS-ANIMA: A modeling and simulation system for sound and image synthesis—The general formalism. Computer Music Journal, 17(1):19–29, Spring 1993.
N. Castagne and C. Cadoz. Creating music by means of physical thinking: The musician oriented Genesis environment. In Proc. 5th Internat’l Conference on Digital Audio Effects, pp. 169–174, Hamburg, Germany, Sept. 2002.
N. Castagne, C. Cadoz, J.-L. Florens, and A. Luciani. Haptics in computer music: A paradigm shift. In Proceedings of EuroHaptics, pp. 422–425, Munich, Germany, June 5-7 2004.