Source rendering on dynamic audio displays
We describe a design for an “audio display”, a loudspeaker that employs the bending vibrations of a panel, such as flat-panel television screen or projection surface, to render localized sound sources anywhere on the surface of the panel. The method employs a two-dimensional Fourier series reconstruction of the desired panel spatial vibration profile, and an array of force actuators affixed to the panel to selectively control its bending modes. The parameters of the signal filters required to drive the actuator array are based upon the intended panel spatial vibration profile and the resonant frequencies and quality factors of the panel modes. A computationally efficient method to dynamically control the locations of the audio sources on the audio display surface is described. Laser vibrometer measurements of a prototype show that the method can be used for real-time control of sound source locations, which allows audio sources and their corresponding video features to be spatially aligned to give viewers a greater sense of media immersion.