This study investigates the potential of "VoiceThread" (VT) as a learning tool in order to enhance learners' performance and confidence, and to provide the basis for continuing independent practice. The participants were students from culturally and linguistically diverse backgrounds on a 10-week English for Academic Purposes (EAP) programme in academic speaking and listening skills in an Australian university. Students carried out a weekly extended speaking task in the form of an academic presentation, on a theme/topic related to their own interests. To prepare for this they used VT to record and rehearse their presentation, uploading their recordings to the Learning Management System for other students to listen to, and for the teacher to provide individual feedback. The recordings were analysed in relation to a number of features to measure utterance fluency, including speed, repairs and pauses. Questionnaires were used to investigate students' perceptions of the value of the task, of their performance on the task, and of changes in their performance and confidence over time. Interviews were used to investigate the potential of recording and rehearsal for long term independent practice. The study involved a total of 34 students in 10 week courses, 22 students using the "VoiceThread" software, and 12 students in a comparison class following the same curriculum, but without the "VoiceThread" software. The results suggest that, over time, regular VT tasks help students develop their performance and confidence in spoken English. Such voice-recording activities have the potential to improve oral performance by encouraging independent practice of oral activities, and so tackling the limitations on time, practice and feedback inherent in classroom-based courses.