Communication is critical to effective collaboration and decision making in both student and professional engineering teams. While teamwork is often assigned at the undergraduate level, the increasing emphasis on preparing students for the workplace has spawned interest in selfdirected student teams that possess a higher degree of autonomy over decision making. This naturalistic study analyzed communication within two self-directed design teams in an undergraduate mechanical engineering capstone course at the Massachusetts Institute of Technology (MIT), in which 8 student-led teams initiated and developed new product prototypes over the semester. Insights presented here, from the first part of the full study, focused on a pivotal, relatively high-stress meeting, in which all 24 members of each team collectively discussed four product options and decided on one product to prototype. The audio recording and transcript of the meetings was used to compare the duration of time devoted to the students' presentations of the four different product ideas, as well as the free-form question-and-answer sessions that followed each presentation. The quantity and distribution of verbal participation from individuals during each Q&A discussion was also calculated. Although limited in scope, results of this first study suggest a correlation between the duration of Q&A sessions, distribution of communication responsibility among individual team members, and final product selection. Furthermore, a total of 23 out of 24 students (96%) on Team A and 20 out of 24 students (83%) on Team B asked and/or answered questions during the discussions throughout the meeting, suggesting that the stress and emotion of the high-stakes meeting may have reduced social loafing and contributed overall to students' verbal participation.