This article provides an overview of a novel ecological momentary assessment method called the electronically activated recorder or EAR. The EAR is a portable audio recorder that periodically records snippets of ambient sounds from participants’ momentary environments. In tracking moment-to-moment ambient sounds, the EAR yields an acoustic log of a person's day as it naturally unfolds. As a naturalistic observation method, it provides an observer's account of daily life and is optimized for the assessment of audible aspects of participants’ daily social environments and interactions. The article discusses the EAR method conceptually and methodologically and identifies three important ways in which it can enrich social health research. Specifically, it can help cross-validate research findings independent of self-reports, calibrate psychological measures against behavioral markers of real-world social functioning, and further our understanding of the role that people's mundane social interactions and language use play in coping and health.