Analytical Study of High Pitch Delay Resolution Technique for Tonal Speech Coding

Problem statement: In tonal-language speech, since tone plays important role not only on the naturalness and also the intelligibility of the speech, it must be treated appropriately in a speech coder algorithm. Approach: This study proposes an analytical study of the technique of High Pitch Delay Resolutions (HPDR) applied to the adaptive codebook of core coder of Multi-Pulse based Code Excited Linear Predictive (MP-CELP) coder. Results: The experimental results show that the speech quality of the MP-CELP speech coder with HPDR technique is improved above the speech quality of the conventional coder. An optimum resolution of pitch delay is also presented. Conclusion: From the analytical study, it has been found that the proposed technique can improve the speech coding quality.