关键词: 基音轨迹, 可变夹角链码（AIAC）, 链码匹配, 相似度

Abstract: The pitch fluctuation and intonation rhythm are reflected by the pitch track as an important parameter in the voice similarity. For characterizing pitch curve accurately, this paper optimized the pitch track which is extracted by AIAC（Alterable Included Angle Chain）. Based on comparing the similarity of pitch curve between imitator and standard pronunciation, the method of extracting pitch curve and matching algorithm of similarity are discussed. And the assessment of pitch characteristics is completed. The results show that the method is simple in calculation process and the results are good.

Key words: pitch curve, Alterable Included Angle Chain（AIAC）, chain code matching, similarity