Audio-graphic conferencing is becoming an important and an integral part of distance/online language teaching and learning. Based on ten years of research into online experience with such systems, this article directs a critical glance at online teaching and learning practices by examining the relationship between socio-constructivism, communicative tasks, technology and language acquisition, in two specific online training courses. The design of tools and communicative tasks draws on a socio-constructivist theory of learning. According to this theory, the active implementation of communicative tasks by learners is an essential condition for learning. However there has been little research on how these socio-constructivist conditions for learning are realized in the specific setting of synchronous audio-graphic conferencing environments. To explore this question, we examine the implementation of communicative/socioconstructivist tasks on two different audio-synchronous platforms. We conclude that the nature of the scenario (or task), the tool and the users (and uses) all have a role in influencing language acquisition in audiographic settings. Our findings also suggest that future research should look at the transferability of practices from one technology to another.