Near-field object-based audio rendering on flat-panel displays

Devices such as smartphones and televisions are beginning to employ the screen as both a video display and a sound-transmitter. This dual-purpose device is well suited for an object-based encoding of audio, where audio objects may be rendered at the location of their corresponding visual images on the screen. The audio object renderer must be configured to account for variations in panel behavior at different excitation frequencies. We propose a multi-band crossover network for the audio object renderer that separates the signal for each audio object into low, midrange, and high-frequency bands, where each band is reproduced on the panel using a different vibration rendering technique. The different rendering techniques are realized by employing a combination of actuator array processing and the natural vibration localization characteristics of point-driven panels. The cutoff frequencies for each band are determined by the physical properties of the panel. Experiments on a prototype panel employing the multi-band crossover system demonstrate that the vibration response behaves as predicted in each frequency range. This system provides a platform for rendering spatial audio on devices where listeners are close to the screen, and restrictions related to weight, power consumption, and form-factor limit the practicality of multichannel surround systems.