Patent ID: 6556687
Filing Date: 2003-04-29
Classification: H04R

Abstract:
A super-directional loudspeaker comprising:a supporting member having a concave surface, wherein a curvature of said concave surface of said supporting member is adjustable; electro-acoustic transducer elements fixed to the concave surface of said supporting member; said elements being designed to receive an electrical input signal and to produce acoustic vibrations according to said electrical input signal thus received, thereby emitting directional ultrasonic waves modulated with an audible frequency signal in the air; and said elements being arranged circularly along said concave surface of said supporting member in such a way that said directional ultrasonic waves emitted by said elements propagate in the air to converge on a listening point in front of said concave surface at a distance sufficient for substantial demodulation of said directional ultrasonic waves.