Comparison of speech perception skills in young and old listeners

A companion paper (Yanz. 1984, Ear Hear. 5, 64-71) has described an approach to the quantification of speech perception using measures derived from the theory of signal detection (TSD). The present experiment uses this approach to compare speech perception in young and old listeners in terms of the traditional word recognition score (%C), the ability to assess the accuracy of one's own identifications [P(A)], and the decision criterion used in that assessment (B). Monosyllables were presented in a background of broadband noise at two signal-to-noise ratios (S/N), 0 dB and 5 dB. Subjects recorded their identification of each test item and then rated their confidence in that identification on a six-point scale. Results indicated that in this particular task, neither %C nor B differed between the two age groups, but both quantities varied with S/N. P(A) was the same for the two groups at S/N = 0 dB but differed at S/N = 5 dB. The young group showed significant improvement in P(A) from the 0-dB to the 5-dB S/N condition, while old subjects showed no change. These results suggest that young subjects are more able than older subjects to adapt to and take advantage of an improvement in the acoustic environment.