Abstract: Disclosed is a method designed to stimulate the presence of one or more sound sources in virtual positions in three-dimensional space, in the perception of a listener occupying a real physical space, by means of suitable drive loudspeakers whose position is not perceived by the said listener, and a device for the implementation of the said method.

Abstract: Cassette changer apparatus for a machine for recording and playing back information on magnetic tape contained in a cassette when located in an operative position. The cassette changer apparatus has a cassette storage magazine and cassette loading apparatus for transporting cassettes between the magazine and the operative position in the machine.A turntable supports the magazine for rotation about an axis extending through the inverting axis for a cassette in the magazine, so that operating the turntable to rotate the magazine one-half revolution inverts a cassette therein and positions both sets of recording racks on tape in the cassette upon transport to the operative position for use with a mechanism providing playback and/or recording upon a single direction of tape movement. The magazine in preferred embodiment has a plurality of compartments and is translatable to bring any compartment and cassette therein to loading position.