Stereophonic sound reproduction for multiple listeners

Reproduced sound through a stereophonic system can produce the illusion of a sound stage in front of the listener. The necessary localization cues for the spatial illusion are created by using a pair of spaced loudspeakers in accordance with either recorded or adjusted audio signals over a certain frequency range. A major problem of this system is that the mentioned spatial illusion can only be created over a small space symmetrically located in the axis between the loudspeakers called the ‘sweet spot’. If the listener moves aside from the sweet spot (asymmetric position), the interaural time difference and interaural level difference (ITD, ILD localization cues), change dramatically and along with the so-called precedence effect, the spatial perception collapses to the nearest of the two loudspeakers. Therefore it can be said that purist stereophonic system works only for one listener at one specific location. This paper explores the possibility to produce the stereo spatial perception for two listeners simultaneously by using only the original arrangement (two loudspeakers). In other words, the possibility of enlarging the sweet spot over a broader area including two listeners