During recent years auditory research has advanced quite rapidly in the area of experimental psychology as well as in that of physiology. Scientists working in both areas have in cornrnon the study of the process in HEARING, yet different scientific areas always tend to diverge. A SYMPOSIUM ON PSY­ CHOPHYSICAL MODELS AND PHYSIOLOGICAL FACTS IN HEARING was or­ ganized for the exchange of information and to stimulate dis­ cussion between research workers in psychoacoustics, neurophy­ siology, anatomy, morphology and hydromechanics. The basic aim of holding this syrnposium was to halt the divergence and to initiate the kind of multi-disciplinary research that will be need ed to elucidate the hearing process as a whole. The present proceedings comprise the papers, which were circulated to the participants two months before the syrnposium and discussed during the syrnposium, together with some cornrnents and additional re­ marks. These cornrnents and rernarks do not, however, represent the full discussions but only the parts available in written form. We have arranged the material in five sections: I. Structure and Neurobiology of the Inner Ear II. Cochlear Mechanisms III. Auditory Frequency Analysis IV. Auditory Time Analysis V. Nonlinear Effects Within the limits of a syrnposium, none of these topics could be treated comprehensively; moreover, most of the papers concerned problems having several aspects.