In a sJries of experiments, we examined age-related differences in adults' ability to order sequences oftones presented at various speeds and in contexts designed to promote or to impede stream segregation. In Experiment 1, 32 listeners (16 young, 16 old) were required to identify two repeating sequences that consisted of four tones (two from a high and two from a low frequency range) in different order. In Experiment 2,32 listeners were required to judge whether the two recycled patterns from Experiment 1 were the same or different. In Experiment 3, four young and four old listeners were tested on the tasks of Experiment 2 over an extended period. In Experiment 4, 16 young and 16 old listeners were tested with sequences that were not recycled and were composed of tones drawn from a narrow frequency range. Elderly adults were less able than young adults to distinguish between tone sequences with contrasting order, regardless ofthe speed of presentation, the nature of the task (identification vs. same/different), the amount of practice, the frequency separation of the tones, or the presence or absence of recycling. These findings provide evidence of a temporal sequencing impairment in elderly listeners but reveal no indication of age differences in streaming processes.There is little understanding of the speech comprehension deficits that occur in later life. Although age-related changes in auditory sensitivity are apparent (for a review, see Robinson & Sutton, 1979), these changes in peripheral processing cannot account for the magnitude of the speech perception problems experienced by elderly listeners (Feldman & Reger, 1967;Hayes, 1981;Olsho, Harkins, & Lenhardt, 1985; Working Group on Speech Understanding and Aging, 1988). Central deficits seem to be implicated (Hawkins & Presson, 1986), but progress in the specification of relevant mechanisms or processes has been limited.Temporal sequencing ability, which is critical to the speech perception process, has been linked to developmental language delays and learning disabilities (Tallal & Stark, 1985a, 1985b. Proficiency in temporal sequencing tasks seems to depend on many factors, including the number of elements in the test sequences, the occurrence of single or repeating sequences (e.g., Warren, 1972), and practice (Divenyi & Hirsh, 1974), as well as on whether the stimuli are speech sounds (Warren, Obusek, Farmer, & Warren, 1969). The response measure is also relevant, with judgments of order yielding poorer performance than same/different judgments (Warren & Byrnes, 1975), and verbal responses yielding poorer performance than nonverbal responses (Warren & Obusek, 1972). In the present investigation, we examined the possibility of temporal sequencing deficits in later life. Grouping mechanisms are also critical to the perception of sound sequences such as speech. The auditory stimuli that reach our ears do not contain separate information from different sound sources, but rather a combination of information from all sources, creating the need for parsing or ...