Much greater spatial realism is obtained by using more than one loudspeaker. Generally a reproduction system having some spatial realism will be preferred to a technically superior monophonic system. This chapter treats the directional ability of human hearing as the basis on which spatial illusions can be created.
7.1 History of stereophony Stereophonic sound is actually older than most people think. The ﬁrst documented public demonstration was in 1881 when Ader used pairs of telephone lines to convey stereo from the Paris Opera.1 A multi-channel cylinder recorder was marketed in 1898.