摘要
为了实现甚低码率下的透明质量语音编码,提出了一种基音周期估计算法。针对语句后部的变调和基音频率的衰减,采用改进的自相关函数计算方法增强快变基音周期的跟踪。基于改进的自相关函数,采用相邻基音周期平滑变化等决策准则确定基音周期估计参考轨迹。算法增强了在鼻化元音的颤音等情况下不规则基音周期的估计。非正式的测试表明这种算法改进了基音周期的估计值,能够极大地降低由于不准确的基音周期估计而引入的听觉失真。
A kind of robust pitch estimation algorithm is presented for parametric speech coding with transparent quality at very low bit rate. We adopt improved computation of autocorrelation function for the case of FO change in the end of sentences, and realize accurate tracking to rapidly changed pitch. Based on decision rules, such as the slow change of pitch between adjacent frames, the improved autocorrelation functions are used to get the robust pitch reference for next steps. Pitch estimation of speech vowel is enhanced. Using conventional pitch track algorithm makes final decision of pitch estimation. Informal tests show that the algorithm could achieve the enhancement of pitch estimation and decrease the perceptual distortion made by improper pitch estimation.
出处
《声学学报》
EI
CSCD
北大核心
2003年第6期540-544,共5页
Acta Acustica
基金
国家自然科学基金(49771064)
国家测绘局测绘科技发展基金(97009)
湖北省自然科学基金(211130494)资助项目
