The role of F0 variation in the intelligibility of Mandarin sentences

This study tested the importance of F0 variation for tone language comprehension. The intelligibility of Mandarin sentences with natural F0 contours was compared to the intelligibility of monotone (flat-F0) sentences created via speech resynthesis. In a quiet background, flat-F0 speech was just as intelligible as natural speech (about 94% intelligible), highlighting the robustness of the language comprehension system. However, when babble noise was added (0 db SNR) flat-F0 speech was substantially less intelligible than natural speech (60% vs. 80% intelligible), indicating that F0 variation is very important for Mandarin sentence intelligibility in noise.