提取淹没在噪声中的周期信号要求自相关（以判断周期）和互相关（以恢复信号自身）-Extraction drowned in the noise requirements of a periodic signal autocorrelation (to determine the cycle) and cross-correlation (to restore the signal itself)

对语音进行分析，包括时域分析（包括能量、过零率、互相关函数）和频域分析（包括fft变换、倒谱、LPC）-Speech analysis, including time domain analysis (including energy, zero-crossing rate, the cross-correlation function) and frequency domain analysis (including fft transform, cepstrum, LPC)