Abstract: An apparatus for sorting paper materials includes a separating mechanism for thinning the paper materials and a sensing mechanism for classifying the paper material according to type. The separating mechanism includes a plurality conveyor belts operating at successively higher speeds, whereby passing materials from one conveyor belt to another conveyor belt results in spreading the paper material. The sensing mechanism includes a mechanical striking device to strike the paper material, a microphone to detect the sound caused by the striking device and an evaluation unit to determine the type of paper material on the basis of the sound.