Synthetic Speech in Computer-Enhanced Foreign Language Learning

The goal of this chapter is to explain several experiments carried out by our research group to explore whether synthetic speech can be currently used to replace natural speech in listening materials for foreign language learning or not. For CALL purposes, synthetic speech in English was evaluated from the viewpoints of both foreign language learners and teachers. We conducted several surveys: (a) to find out if the synthetic speech generated by current TTS engines is as efficient as natural speech in training listening skills, (b) to identify the specific ways in which the evaluated synthetic speech is as good as natural speech, (c) to determine the relationship between changes in individual listening comprehension ability and the results of the quality evaluations of synthetic speech, and (d) to discuss the possible approaches for using synthetic speeches.