Purpose: To test the effects of 24 hr of sleep deprivation on auditory and linguistic perception and to assess the magnitude of this effect by comparing such performance with that of aging adults on speech perception and with that of dyslexic readers on phonological awareness. Method: Fifty-five sleep-deprived young adults were compared with 29 aging adults (older than 60 years) and with 18 young controls on auditory temporal order judgment (TOJ) and on speech perception tasks (Experiment 1). The sleep deprived were also compared with 51 dyslexic readers and with the young controls on TOJ and phonological awareness tasks (One-Minute Test for Pseudowords, Phoneme Deletion, Pig Latin, and Spoonerism; Experiment 2). Results: Sleep deprivation resulted in longer TOJ thresholds, poorer speech perception, and poorer nonword reading compared with controls. The TOJ thresholds of the sleep deprived were comparable to those of the aging adults, but their pattern of speech performance differed. They also performed better on TOJ and phonological awareness than dyslexic readers. Conclusions: A variety of linguistic skills are affected by sleep deprivation. The comparison of sleep-deprived individuals with other groups with known difficulties in these linguistic skills might suggest that different groups exhibit common difficulties.