In the regular flow of human conversation, we send many signals to each other about what we do and do not know. This talk examines what sociologists call “the epistemic backchannel”, with an eye to understanding its purpose and its impact on communication. Empirical work on representations of the epistemic gradient between speakers can help philosophers understand the social division of epistemic labor. At the same time, empirical theories of what is happening in the backchannel can be improved by philosophical attention to the distinction between knowing and merely seeming to know.