The main objective of this paper is to examine the use of audio- versus text-based asynchronous online discussions. We report two case studies conducted within the context of semester-long teacher education courses at an Asian Pacific university. Forty-one graduate students participated in Study I. After the online discussions (both audio-based as well as text-based) had ended, qualitative data via student reflections were collected. Results revealed that audio-based discussions have six distinct perceived affordances compared to text-based ones. Interestingly, despite the reported affordances, more than half of the students reported that they preferred to use a text-based discussion if given a choice. The main reasons for their preference were explored. In Study II, 42 undergraduate students took part. Similar to Study I, participants in Study II also indicated that they felt more comfortable using a text-based discussion. The reasons for their preference were also discussed. Directions for future research are proposed.