This paper discusses how synchronizing Web 2.0 technologies, particularly by using VoiceThread, is able to help English speaking teachers to improve their formative feedback in the teaching of speaking skills. This study shows that the use of VoiceThread able to become one of the solutions to help teachers who want to provide specific, clear and accurate feedback on oral performance activities. This study is an action research, which involves six EFL learners at one of the universities in Indonesia. Before VoiceThread can contribute to improving teachers’ formative feedback, this study found that teachers need to do the following five matters, they are: (1) Making learners profile; (2) Making lesson plan; (3) Understanding formative feedback; (4) Determining assessment rubric, and (5) Implementing VoiceThread. Implementing VoiceThread is not only designed to help teachers improve their formative feedback, but also make their students able to notice and learn their teacher’s formative feedback afterward. To achieve these objectives, the result of this action research study indicates that giving formative feedback by using VoiceThread is worthwhile since it is a mechanism that combines the asynchronous learning and face-to-face. Thus, this can be considered as an action research on blended learning.