Abstract: In this research, the role and the mechanism of prosodic features in disambiguating demonstrative ambiguous sentences were studied. Thirteen subjects determined the first and second meaning of the ambiguous sentences. One of 8 speakers was selected to read the experiment sentences by professional acoustician and ordinary people. There were 12 subjects in the experiment of stress perception and experiment of meaning decision separately. In experiment 1, the subjects were asked to determine the more stressed word between the demonstrative noun and the non-demonstrative noun. In experiment 2, different kinds of word grouping were inserted into the first meaning sentence frame and the second meaning frame. The subjects were asked to determine whether the combined sentence conveys the first meaning or the second meaning. In experiment 3, we did acoustic measurement and analysis on the nouns in the ambiguous sentences. Results showed that: the way to disambiguate demonstrative ambiguous sentences is to stress the corresponding word by lengthening its duration.

Key words: prosody, disambiguity, demonstrative ambiguous sentences