Sound-source localization on flat-panel loudspeakers

A method is described for creating a two-dimensional audio display by spatially controlling the bending vibrations of a panel. This method can simultaneously produce multiple audio sources on the surface of the panel using an array of independent force actuators to govern the size, shape, and location of each source. The minimum size of a source is determined by the spatial Nyquist frequency of the exciter array, and the spatial vibration profile of the panel may be dynamically controlled through signal processing. Demonstrations on a prototype panel with an optimized array of eight force exciters show that the vibration profile of the panel closely approximates the user-defined target shape at all frequencies within the bandwidth of the actuator array. Target shapes can be independently superimposed, giving the panel the capability of simultaneously reproducing multiple primary audio sources. In addition to primary source reproduction, one or more flat-panel loudspeakers employing this method can be used to render a specific sound-field for applications such as beam-forming or wave-field synthesis.