Tone threshold, speech intelligibility by the Freiburg test with loss of hearing for speech, discrimination loss and total word intelligibility, dichotic discrimination and binaural summation ability were all measured in 167 test subjects aged between 65 and 91 years. The statistical processing of the numerous parameters shows that all parameters manifest a worsening of hearing with age, the individual values revealing a considerable scatter. Tone loss proved to be largely cochlear in nature. All the speech audiometric parameters correlated highly significantly (binaural summation significantly) with age, in the sense that increasing was accompanied by a worsening of the hearing ability. The complex correlations among all the hearing parameters lead us to believe that ageing affects the organ of hearing as a whole, and not merely specific parts of the auditory pathway. A possibility for differentiating between the elements of primary and secondary presbyacusis, and for measurement of the biological age of the sense organ, ear, is discussed.