Pitch Detection Method of Speech Signal by Amplitude Ratio of Variable Bandwidth Lowpass Filter

摘要

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a pitch by means of an average amplitude ratio when a voiced sound waveform passes through a variable bandwidth LPF in the time domain by processing voice in an electronic aspect.;To obtain this pitch, vary the cutoff rate of the lowpass filter within the range of 10.6 to 32 where the first formant is present for each frame, and determine the most suitable cutoff band of the frame by the amplitude ratio obtained. The low pass filter was used to obtain G-peak, and the pitch was obtained.;In the present invention, since the pitch is directly detected in the time domain, the processing method is simplified, the pitch detection is improved, the accuracy is improved, and the influence of the speaker in speech recognition can be reduced, so that the recognition accuracy can be increased. It is easy to change or maintain nature and personality. In addition, the analysis in synchronization with the pitch has the advantage of obtaining accurate saint parameters with the influence of the gates removed.