利用Hilbert-Huang变换的自适应带通滤波特性提取共振峰

Finding speech formant by using the character of Hilbert-Huang transform as an adaptive band-filter

利用Hilbert-Huang变换的自适应带通滤波特性,提出了一种共振峰提取算法。该算法利用固有模态函数是均值为零的窄带调频调幅信号与语音信号声道模型的调频-调幅信号相一致的特点;并根据经验模态分解的自适应性,有效地利用了信号本身决定固有模态函数的中心频率和带宽的特性,不需预先估计带通滤波器频率和带宽便可得到共振峰分量,避免受虚假峰值、共振峰合并和高音调语音的影响。该算法既能精确提取共振峰,又能跟踪共振峰频率的变化。

A novel algorithm of finding the speech formant frequency by using the character of Hilbert- Huang transform as an adaptive band-filter is proposed. The algorithm utilizes the character that the intrinsic mode functions, which are zero mean narrow band frequency-amplitude modulation signals, are consistent with the frequency-amplitude modulation model of speech perfectly. Besides, according to the adaptability of empirical mode decomposition, the character that the signal itself decides the frequency and band of intrinsic mode functions is effectively applied Thus the formant components can be obtained without having to estimate the frequency and band of the band-filter in advance, and the influence of the interference of false peaks, merged formant and high-pitch voice can be avoided. This algorithm not only can accurately extract the ormant, but also can track the changes of the formant.