噪声环境下的基音检测在语音信号分析和识别中占有重要地位。二次谱法是基于倒谱法的一种改进的基音检测方法。本文结合二次谱法和小波变换的去噪特性，提出了一种有效的噪声环境下的基音检测方法。实验表明，在信噪比较低的情况下，该法也能较精确的检测基音周期。关键词：基音检测；小波变换；二次谱法Abstract: Pitch detection in noisy environment plays an important role in speech analyzing and recognition. Second spectrum is an improved method based on cepstrum . Combined the second spectrum with the denoise characteristic of wavelet transform, An effective method is proposed in this paper. Through simulation experiments, it is shown that it behaves more robustly and can detect pitch more accurately at low signal-to-noise ratio.Key words: Pitch detection；Wavelet transform；Second spectrum