Application of Three-Dimensional Audio to Copyrighted Multimedia Contents

Copyright is important to protect proprietary properties of multimedia contents, but it possibly poses a challenge in applying complicated signal processing to commercial multimedia products. It is usually forbidden to make a copy of copyrighted materials so that signal processing should be applied on the fly. As a result, such signal processing needs considerable computational costs and requires special devices and software, leading users to hesitate to adopt it. In this article, a method is introduced which enables users to listen to surround sound audio tracks as three-dimensional (3D) audio, without infringement of copyright, with a common multimedia player currently available on a usual PC. The 3D sound can be one that would be heard in an appropriate listening room with a set of ideal loudspeakers, and also can be properly individualized to each listener. Although the method adds a temporal delay in audio contents relative to visual contents, the delay can fall within an acceptable range with respect to the human perception of multimedia contents.