Recognition of interrupted speech requires connecting speech fragments over time and across gaps of missing information. Intelligibility improves when silent intervals are filled with noise; the effect is enhanced when noise contains rudimentary speech information, such as the temporal envelope of the missing speech. In multiple-talker environments, recognition of interrupted speech is more difficult, particularly for older adults. In these cases, temporal envelope cues may provide an important scaffold for auditory object formation. Other basic speech cues, such as F0-related periodicity, may help listeners segregate multiple voices and provide additional benefit. The relative, and potentially additive, benefit of temporal envelope and periodicity cues, and their use by older adults, remain unclear. To address these questions, younger and older adults with normal hearing listened to sentences in quiet and competing talker backgrounds. Sentences were periodically interrupted with (1) silence, (2) envelope-modulated noise, (3) steady-state pulse trains, which contained periodicity information from the missing speech, or (4) envelope-modulated pulse trains, which provided both envelope and periodicity information. Results are discussed in terms of contributions of temporal envelope and periodicity cues to perceptual organization for younger and older adults listening in complex environments. [Work supported by NIH/NIDCD and a AAA Student Investigator Research Grant.]