In earlier work, we identified a 110 millisecond region of low pitch as a prosodic feature which seems to bear the dialog function of encouraging back-channel feedback from the listener. In this paper, we examine the ways in which this prosodic feature co-occurs with semantic, pragmatic, and lexical events. Both subjective analysis and statistical analysis suggest that low-pitch regions are associated with the completion or near-completion of the transmission of some unit of information, the occurrence of a disluency, and the occurrence of back-channel feedback. We take this as evidence that low-pitch regions are real prosodic features.