Abstract
Two series of speech identification tests were conducted in different age groups, the first test consisting of 11 synthetic speech stimuli varying in vowel length, the second test being composed of 30 natural speech stimuli varying in length of the initial consonant. Categorical perception of different phonemes was demonstrated in both experiments in all age groups. Persons more than 65 years of age showed significantly lower response percentages in both tests than did younger subjects. In the test where natural speech stimuli were used, boundaries of phoneme-category shift were dislocated in the older when compared with results of the younger subjects. Furthermore, speech discrimination was poorer in monaural than in binaural listening condition in the groups of more than 65-year-old persons with signs of age-induced sensorineural hearing loss: in this age group women showed clearly better results than men. These differences could not be demonstrated in the younger age groups.