Effect of vocal cord polyp on monophthongs with Mandarin tones

This paper investigates effect of unilateral vocal cord polyp on different monophthongs ([-A], [-γ], [-o], [-u]) with Mandarin tones. First, acoustically, Praat was used to extract F0 contour in Mandarin tones to analyze how vocal cord polyp affects F0 contour of different monophthongs with Mandarin tones. Second, perceptually, identification test was used to analyze how vocal cord polyp influences identification rate of different monophthongs with Mandarin tones. In this research, the main findings are as follows: first, vocal cord polyp does not affect tone pitch, F0 contour and identification rate of [-o] with Tone 1. Second, vocal cord polyp has an effect on tone pitch of [-a] with Tone 2 and Tone 3, [-γ] with Tone 2 and Tone 4, [-u] with Tone 4 and [-o] with Tone 4. Third, vocal cord polyp influences F0 contour of [-a] with Tone 1 and Tone 4, and [-γ] with Tone 1 significantly. Fourth, vocal cord polyp has an effect on tone pitch and significantly affects F0 contour of [-γ] with Tone 3, [-u] with Tone 3 and [-o] with Tone 2 and Tone 3. Fifth, vocal cord polyp affects tone pitch and has a significant effect on identification rate of [-u] with Tone 2. Sixth, vocal cord polyp influences tone pitch, and significantly affects F0 contour and identification rate of [-u] with Tone 1. It is concluded that although vocal cord polyp has an effect on tone pitch and F0 contour of monophthongs with Mandarin tones, and has little influence on intelligibility of Mandarin monophthongs except of [-u] with Tone 1 and Tone 2.