EN
This paper aims to prove that the basic function of audition is similar to the function of vision. Both perceptual faculties provide us with information about objects in an environment. Vision helps to extract information from electromagnetic waves and audition extracts it from acoustic waves. The auditory recognition of objects in an environment is a complex task. It cannot be accomplished in a one-level process. Inspired by Marr's proposal, we postulate that auditory information extracted from natural (environmental) sounds is processed on three levels. These are: the level of acoustic audition, the level of auditory spacing (the localization and distance of a sound source), and the level of auditory recognition of an object's properties (such as its motion, weight, size, form or material). The assumption that the auditory system performs different tasks on each level needs empirical support. We designed and performed experiments to test some of these processes. The first experiment investigated the perception of 'auditory contours'. In the second the auditory estimation of differential mass thresholds was examined. In the third experiment, the auditory perception of the velocity of a moving sound source was studied. In consequence, the differential velocity thresholds of the sound source were identified.