A pair of experiments addressed two questions regarding listeners’ sociolinguistic knowledge: First, how do listeners use facts about speech to inform their beliefs about speakers? Second, and conversely, how might listeners use facts about speakers to inform their perceptions of speech? Results of Experiment 1 demonstrate that listeners can infer characteristics of speakers from their use of an individual sociolinguistic variable. Results of Experiment 2 show that listeners use social information about speakers to understand ambiguous speech. Together, these results show bidirectional influences between language processing and the process of social inferencing: information in the speech stream affects inferences about social characteristics of the speaker, and social information affects speech perception.