Abstract: An audio signal processing arrangement includes a first filter (20) for splitting off signal components from the left channel signal (L) at least within one frequency band. Signal components are split off from the right channel signal (R) by a second filter (23). The output signals of the filters (20 and 23) are compared with the right channel signal (R) and the left channel signal (L), respectively. The filter parameters of the filters (20 and 23) are adjusted to values at which there is maximum correlation between the compared signals according to a given criterion. The center channel signal is derived in dependence on the filter adjustment. This can be effected by combining the output signals of the filters (20 and 23).

Abstract: A carrier containing information which is suitable for visual perception, such as a text or a picture. By suitable positioning, a code also present on the carrier linked thereto. This code is visible to the user, but cannot be read directly. A device for reading the code having a scanner which can be moved into the area of the code by hand. The code is optically read, synchronization signals being obtained from the code itself. The information read is stored in an intermediate memory. The intermediate memory is subsequently read under the control of a clock. This data can either directly activate an acoustic generator for producing a sound signal, or can address an object memory which in its turn supplies data for controlling the acoustic generator. A sound signal is thus linked to the picture or the text. A device of this kind may form part of an educational system.