AUDITIVE AND COGNITIVE-FACTORS IN SPEECH-PERCEPTION BY ELDERLY LISTENERS .3. ADDITIONAL DATA AND FINAL DISCUSSION

In a previous study [van Rooij and Plomp, J. Acoust. Soc. Am. 88, 2611-2624 (1990)], it was found that speech-perception performance in a sample of elderly subjects tested in the laboratory may be largely determined by two statistically independent components: (1) a major component representing the progressive middle- to high-frequency hearing loss with age and (2) a minor component mainly representing a general decrement in cognitive performance. In the present study, a selected subset of tests used in the laboratory study was administered to a group of elderly subjects less likely to participate in laboratory experimentation. The results show that approximately all the systematic variance with respect to speech-perception performance, as tested by speech-reception thresholds (SRTs), can be accounted for by the audiogram alone. The implications of the results of the present study and those of earlier ones [van Rooij. Plomp, and Orlebeke, J. Acoust. Soc. Am. 86, 1294-1309 (1989) and van Rooij and Plomp, J. Acoust. Soc. Am. 88, 2611-2624 (1990)] are critically evaluated. It is concluded that age differences with respect to speech perception are most likely due to differences in auditive factors.