THE PERCEPTION OF PREPHONEMATIC ACOUSTIC SIGNALS ALTERS WITH AGE

Presently we are establishing two sets of psychoacoustic tests (basic tests and integrational tests) which should allow the differentiation of peripheral and central auditory processing in normal-hearing and hearing-impaired subjects. In a baseline study performed on one hundred, 20-70 years old normal-hearing subjects we used these tests to evaluate age-dependent alterations in auditory processing. The basic tests measured (1) the monaural audiogram, (2) the frequnecy resolution and the limits of simultaneous (3) frequency and (4) intensity discrimination. The integrational tests reported here evaluate the limits of binaural (5) frequency, (6) intensity and (7) temporal discrimination. These measures, together with tests under successive stimulus conditions, show that temporal processing and processing of stimulus frequency worsens with increasing age, while the processing of stimulus intensity remains stable.