Generation of independent bright zones for a two-channel private audio system

A private audio system is investigated. This system allows a user to enjoy two-channel sound in privacy without headphones. Most commercial audio sounds provide two-channel audio signals recorded via binaural or stereo recording techniques. Therefore it is useful to generate, separately, acoustically bright zones, which are fed by each of the two-channel audio signals, and simultaneously, acoustically dark zones elsewhere. The authors create independent bright zones in the vicinity of a user's ears, together with dark zones in the side regions of the user, practically realizable via acoustic contrast control. A method to make a two-channel private audio system possible, using a linear loudspeaker array, and a means for evaluating the system performance are suggested and experimentally verified.