Pitch extraction and correcting method in speech signal

Abstract

The invention discloses a pitch extraction and correcting method in a speech signal. The pitch extraction and correcting method includes the following steps that a cyclical average magnitude and function of a voiced sound frame is calculated, a cyclical average magnitude difference function of the voiced sound frame is calculated, the cyclical average magnitude difference function and the cyclical average magnitude and function are subjected to a weighted arithmetic, a peak point of a weighting function is searched, a delay point which the peak point corresponds to is recorded, the delay point is a pitch period initial estimated value which corresponds to the voiced sound frame, and according to the pitch period initial estimated values of all voiced sound frames, pitch period initial estimated values are corrected by a post-processing technology based on local voiced sound sections. The pitch period initial estimated values of the voiced sound frames are extracted by the aid of the fact that the cyclical average magnitude and function is weighed by the cyclical average magnitude difference function, the peak point in a pitch period can be effectively highlighted, the antinoise performance is improved, and accurate speech extraction and detection can be achieved in the noisy environment.

Description

technical field [0001] The invention relates to the field of speech signal processing, in particular to a pitch extraction and correction method in a speech signal. Background technique [0002] In the process of human pronunciation, the lungs and the muscles connected to them are equivalent to the excitation source of the entire vocal tract system. When the vocal cords are in a tense state, the airflow from the lungs will cause the vocal cords to vibrate, and the sound produced at this time is called a voiced sound (Voiced sound), conversely, a sound without vocal cord vibration is called an unvoiced sound (Unvoiced sound). The frequency at which the vocal cords vibrate is the pitch frequency, and the inverse of the pitch frequency is the pitch period. The detection of pitch cycle or pitch frequency is referred to as pitch detection (Pitch detection), also known as pitch estimation (Pitch estimation) or pitch extraction (Pitch extraction). Or the trajectory curve that mat...

AI Technical Summary

Problems solved by technology

Although there are many pitch detection algorithms for clean speech signals, there are relatively few researches on pitch detection for speech signals with noise, and the progress is relatively slow. The detection accuracy of many algorithms decreases significantly in the presence of noise, and even cannot detect

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