The natural conversations and social environments of 52 undergraduates were tracked across two 2-day periods separated by 4 weeks using a computerized tape recorder (the Electronically Activated Recorder [EAR]). The EAR was programmed to record 30-s snippets of ambient sounds approximately every 12 min during participants' waking hours. Students' social environments and use of language in their natural conversations were mapped in terms of base rates and temporal stability. The degree of cross-context consistency and between-speaker synchrony in language use was assessed. Students' social worlds as well as their everyday language were highly consistent across time and context. The study sheds light on a methodological blind spot--the sampling of naturalistic social information from an unobtrusive observer's perspective.