Virtual loudspeakers for acoustically opaque screens

A method of providing audio from an acoustically opaque screen using wave field synthesis (WFS), the method comprising:

• providing a plurality of acoustic transducers arranged as a WFS transducer arrangement relative to the acoustically opaque screen;
• driving the plurality of acoustic transducers to generate at least one acoustic wavefront formed from a plurality of elementary waves;
• delaying selected ones of the plurality of elementary waves relative to others according to a WFS principle to generate a curvature of the at least one acoustic wavefront;
• radiating the at least one acoustic wavefront toward the acoustically opaque screen such that, in an azimuthal plane, the plurality of elementary waves arrives substantially simultaneously at a region proximate to the acoustically opaque screen;
• focusing the at least one acoustic wavefront at a location in front of or behind the acoustically opaque screen;
• reflecting the at least one acoustic wavefront from the acoustically opaque screen to form at least one reflected acoustic wavefront directed to be received within a spectator area;
• and
• configuring the curvature of the at least one acoustic wavefront such that, upon reflection from the acoustically opaque screen, the at least one reflected acoustic wavefront creates a perceptual effect of originating from a defined region on or near a surface of the acoustically opaque screen that corresponds to a sound source optically represented in the defined region of the acoustically opaque screen,
• wherein the curvature of the at least one acoustic wavefront emanates from the plurality of acoustic transducers concavely in the azimuthal plane and convexly or concavely in an elevation plane.

An acoustic transducer arrangement for use with an acoustically opaque wall display, comprising:

• a two-dimensional array comprising a plurality of acoustic transducers;
• and
• a controller configured to individually drive the plurality of acoustic transducers to emit a plurality of elementary acoustic waves that combine to form at least one acoustic wavefront directed toward the acoustically opaque wall display, the controller being configured to:
• apply respective time delays to the plurality of elementary acoustic waves in accordance with a wave field synthesis (WFS) principle to synthesize the at least one acoustic wavefront with a curvature that is concave in an azimuthal plane and concave or convex in an elevation plane,
• cause the plurality of elementary acoustic waves to arrive substantially simultaneously at a focal region proximate to the acoustically opaque wall display, such that, upon reflection by the acoustically opaque wall display, at least one reflected acoustic wavefront propagates into a spectator area, and
• apply respective amplitude/level weights to individual ones of the plurality of acoustic transducers such that, after reflection by the acoustically opaque wall display, an acoustic pressure level in a direction toward spectators farther from the acoustically opaque wall display is greater than an acoustic pressure level in a direction toward spectators closer to the acoustically opaque wall display to provide a substantially balanced acoustic pressure level across the spectator area,
• wherein the at least one reflected acoustic wavefront creates a perceptual effect of originating from a defined region on or near a surface of the acoustically opaque wall display corresponding to a visually represented sound source in the defined region.