关键词: 波形修正算法（WEM）, 基音周期（PITCH）, 平均幅度差函数（AMDF）, 变长平均幅度差函数（LV-AMDF）, 循环平均幅度差函数（CAMDF）

Abstract: A short time pitch detection algorithm based on waveform extremum is proposed. Speech extremum is extracted after denoised and voiced / unvoiced detected, then the waveform extremum is modified. Magnitude difference is calculated, and pitch is detected by a certain pitch criterion. The algorithm, with high accuracy, does not need divided window processing, and main calculation is waveform extremum processing and has a smaller amount of calculation than common AMDF. Experimental results show that this method can get accurate pitch and is suitable for real-time processing.

Key words: Waveform Extremum Method（WEM）, pitch period, Average Magnitude Difference Function（AMDF）, Length Variable-Average Magnitude Difference Function(LV-AMDF), Circular Average Magnitude Difference Function（CAMDF）