A study investigated differences in discourse styles that may affect second language listening comprehension. Ten amateur actors performed three speaking tasks: (1) reading aloud a short self-contained narrative; (2) acting out a memorized script; and (3) conversing with the researcher for 20-30 minutes. Excerpts of the recorded tasks in different discourse modes were analyzed for fundamental frequency, speech burst duration, duration of silence between speech bursts, and proportion of time devoted to speech. Results were compared for the discourse types. Analysis of the results for two variables (fundamental frequency and silence duration) found some significant differences between the discourse styles, with acting highest and conversation lowest in fundamental frequency. Acting showed the greatest amount of fluctuation around the mean fundamental frequency value (i.e., use of potential pitch range), and conversation the least. Duration of silences was also greatest in acting and shortest in conversation. Speech articulation occupied the greatest amount of time in conversation and the least in acting. Findings suggest that contrasting discourse styles or genres do have distinctive prosodic characteristics, and that conversational material is likely to be more difficult to comprehend than other discourse types, making careful selection and ordering of these materials essential. A 26-item bibliography is included. (MSE)