Audio Projection

The ability to control sound radiation patterns in entertainment, gaming, communication, and personal messaging is becoming an important differentiating feature in many commercial products. A common feature in these systems is to -create a highly directional sound field to targeted audiences by forming a tune-in zone (or personal audio) for a group of -people. There are several ways to generate the directional sound field, which include i) using a sound dome that projects sound to a convex surface to focus sound wave to the listeners below the sound dome; ii) using a loudspeaker array that adjusts its phase-amplitude difference among the loudspeakers to spatially steer the audible sound beam in a horizontal plane; and iii) modulating an audible sound signal onto an ultrasonic carrier and projecting the modulated signal via special types of ultrasonic emitters to generate the parametric array through the air, in such a way that audible sound can travel in a column of sound beams. This latter group of loudspeakers is commonly called the parametric (or ultrasonic) loudspeakers. © 2010 IEEE.