Interaction is a necessary condition for second language (L2) learning (Long, 1980, 1996). Research in computer-mediated communication has shown that interaction opportunities make learners pay attention to form in a variety of ways that promote L2 learning. This research has mostly investigated text-based rather than voice-based interaction. The present study applied "form-focusing information gap tasks" (Pica, Kang, & Sauro, 2006) to a voice-based computer-mediated environment and investigated whether individual or interactive task performance conditions affect language development differently. This is a relevant research question for distance language learning programs, which are primarily asynchronous and largely rely on individual performance and text-based communication. The results of the study showed significant pre-to-post learning gains under both performance conditions (individual and interactive). Between-groups comparisons further showed that participants in the interactive condition outperformed participants in the individual condition on two of the three target structures investigated.