Audio beam : a new type of loudspeaker design

• Main Authors: Gan, Woon Seng, Er, Meng Hwa, Yang, Jun
• Other Authors: School of Electrical and Electronic Engineering
• Format: Research Report
• Published: 2008
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Home entertainment systems
• Online Access: http://hdl.handle.net/10356/2855
• Institution: Nanyang Technological University

Audio Beam is a revolutionary way of projecting audio signals in a highly directional manner to the listener. Instead of using conventional large loudspeaker arrays for projecting a narrow sound beam to the listener, this new technique creates the same narrow beam by amplitude-modulating the audio signal with a finite amplitude ultrasonic carrier wave and then transmitting the resultant signal from an array of ultrasonic transducers across the air to the listener. As a result, an audio signal is automatically produced by the self-demodulation effect of the amplitude-modulated sound wave in the air, without the aid of any hearing device. With this nonlinear interaction, we develop a new type of loudspeaker capable of controlling the direction of the transmitted audio signal.