A study at Sultan Qaboos University in Oman investigated the listening comprehension problems of students who were non-native speakers of English (NNS), in lectures by native English-speaking professors. Two professors with no previous experience in teaching non-native speakers introduced geology in 4 weeks of lectures. Instances of vocabulary elaboration in the lectures were analyzed, including all uses of special terminology or expressions that the teachers in some way qualified, explained, questioned, repeated, paraphrased, or expanded on; analogies were included. For each elaboration, occurrence of these features was recorded: type and complexity of elaboration; discourse markers; speed and stress; overt signals of importance; type of explanation; and technicality of terms used. This information was analyzed for patterns of teacher language use and individual differences between teachers. Some elaborations were very complex, with further elaborations embedded in them. Student notes on one topic were then examined for insight into the lecturer's method of explaining and the way students recorded the information. Results indicate students were unaware of many lecturer cues signaling key base words, and had difficulty extracting them from the ongoing discourse. Notes showed poor organization. Suggestions are made for improving NNS students' listening and note-taking skills. (MSE)