Hoppe, D., Sadakata, M., & Desain, P. (2006). Development of real-time visual feedback assistance in singing training: a review. Journal of computer assisted learning, 22, 308-316.
Four real-time visual feedback computer tools for singing lessons (SINGAD, ALBERT, SING & SEE, and WinSINGAD), and the research carried out to evaluate the usefulness of these systems are reviewed in this article. We report on the development of user-functions and the usability of these computer-assisted learning tools. Both quantitative and qualitative studies confirm the efficiency of real-time visual feedback in improving singing abilities. Having addressed these findings, we suggest further quantitative investigations of (1) the detailed effect of visual feedback on performance accuracy and on the learning process, and (2) the interactions between improvement of musical performance and the type of visual feedback and the amount of information it presents, the skill level of the user and the teacher's role.