Modeling Mandarin tones is one of the most important issues in speech synthesis. However, established knowledge is mainly focused on the "production" aspect. In this paper, we first characterized relative pitch levels of tones. Next, two perceptual experiments were designed to investigate "perceptual" relevance of pitch levels and shapes in Mandarin. Results showed that relative pitch levels of tones were perceptually more important than exactness of pitch shapes, and humans could not perceptually distinguish tonal variations in synthesized Chinese names.
Bibliographic reference. Chen, Shi-Han / Kuo, Chih-Chung (2007): "Perceptual relevance of pitch contours of Mandarin tones and its efficacy in prosody generation of speech synthesis", In INTERSPEECH-2007, 2669-2672.