Previous studies have suggested many technologies to support nonnative speaker comprehension in real-time communication. However, such technologies may impose an extra burden on non-native speakers (NNSs) if they do not match their current needs. To design a system that adapts to the changing needs of NNSs, we need to understand the types of problems NNSs face and how these problems are perceived by them. To explore such issues, we conducted a laboratory experiment with 40 NNSs (and 20 native speakers as a control group) who engaged in a listening task. During the task, the participants pressed a button whenever they encountered a comprehension problem. Next they explained each problem, the point at which they recognized the problem, and for how long it persisted. Our analysis identified twelve types of listening comprehension problems, which we further classified into three patterns based on their persistence and the time taken to perceive them. Our findings have implications for designing adaptive technologies to support listening comprehension of NNSs in real-time communication.