Syllable identification by younger and older adults

Abstract

Three synthesized syllables differing in place of articulation ([bɑ], [dɑ], and [gɑ]) were used in a three-alternative identification task. Preliminary trials established the range of stimulus levels at which each S's performance, for each syllable, varied from below 50% to nearly 100% correct. Each of the three syllables was presented at five different intensities differing in 5-dB steps. The three syllables and the five levels for each syllable were presented in intermixed random orders. Listeners (18–23 and 60–75 years old) all had normal hearing for their ages. Syllable identification thresholds (i.e., levels required for 50% correct performance) were higher for the older adults, as might be expected because of their poorer sensitivity. Older listeners also exhibited more shallow identification functions—an outcome that cannot be attributed to sensitivity differences since stimulus levels were adjusted for individual subjects. Possible explanations for these shallow slopes are considered. [Work supported, in part, by NSF.]