Collaboration is a key element of many communicative interactions. Analyzing the effect of collaborative interaction on subsequent decision-making tasks offers the potential to quantitatively evaluate criteria that are indicative of successful communication. While many studies have explored how collaboration aids decision-making, little is known about how communicative barriers, such as loud background noise or hearing impairment, affect this process. This study investigated how collaborative triadic conversations held in different background noise levels affected the decision-making of individual group members in a subsequent individual task. Thirty normal-hearing participants were recruited and organized into triads. First, each participant answered a series of binary general knowledge questions and provided a confidence rating along with each response. The questions were then discussed in triads in either loud (78 dB) or soft (48 dB) background noise. Participants then answered the same questions individually again. Three decision-making measures – stay/switch behavior, decision convergence, and voting strategy - were used to assess if and how participants adjusted their initial decisions after the conversations. The results revealed an interaction between initial confidence rating and noise level: participants were more likely to modify their decisions towards high-confidence prior decisions, and this effect was more pronounced when the conversations had taken place in loud noise. We speculate that this may be because low-confidence opinions are less likely to be voiced in noisy environments compared to high-confidence opinions. The findings demonstrate that decision-making tasks can be designed for conversation studies with groups of more than two participants, and that such tasks can be used to explore how communicative barriers impact subsequent decision-making of individual group members.