分类: 计算机科学 >> 自然语言理解与机器翻译 提交时间: 2016-06-18
摘要: This letter presents a perceptually weighted analysis -by-synthesis vector quantization (VQ) algorithm for low bit rate MFCC codec. Different from conventional VQ of MFCCs vector, this algorithm uses an analysis-by-synthesis technique and aims to minimize the perceptually weighted spectral reconstruction distortion rather than the distortion of MFCCs vector itself. Also, to reduce the computational complexity, we propose a practical suboptimal codebook searching technique and embed it into the split and multistage vector quantization framework. Objective and subjective experimental results for Mandarin speech show that the proposed algorithm yields intelligible and natural sounding speech for speech coding at 600--2400 bit/s. Compared to current VQ in MFCC codec, the output speech quality is substantially improved in terms of frequency-weighted segmental SNR, STOI, PESQ and MOS score.