ABSTRACT
Acoustical communication is possible thanks to the fact that we have an organ that is sensitive to pressure fluctuations in the medium (air) in which we live. A similar or analogous organ is to be found also in more primitive beings and here the function of this organ is clear: it warns the organism of danger and makes it aware of the presence of food etc. This is the primary function of our hearing organ. The sound signals here are irregular and often pulse-like (the breaking of a twig, the falling of a stone, the noise of water etc.). This fact is very important for a proper insight into the functioning of the ear. For perception experiments, for example, we should not restrict ourselves to regular stimuli such as sinusoidal vibrations. This holds especially for directional hearing because this ability is directly connected with the warning function of the hearing organ. Also the strong tendency people have to identify unknown sounds (for example electroni cally generated sounds) can be related to this function.
