漢語韻律微結構模式的初步研究

Abstract

本論文對三種最主要的韻律聲學參數做微結構的初步研究，包括基頻軌跡、音長、能量軌跡，本研究以音素做為分析單位，分析一個包含四種不同語速之平行語料庫的三種音素聲學韻律參數的變化。首先，將此語料庫之語句信號以強迫對準切割成音素序列，並且對此語料庫使用非監督式韻律標記與模式方法，做自動停頓及韻律狀態的韻律標記。研究主要是探討語言參數及兩類韻律標記對音素長度、音素能量軌跡、以及音素的基頻存在機率的影響，方法是使用決策樹，將各種影響因素以問題形式加入，來決定在各種前後文的情況下三種音素聲學韻律參數的估計值，實驗結果顯示此做法可以改善此三種韻律參數的合成。

A preliminary study on the microstructure of Mandarin speech prosody is conducted in this thesis. The variations of three phoneme-based prosodic-acoustic features on a large speech corpus containing four parallel sub-corpora are explored. They include phone duration, phone energy contour, and phone’s occurrence probability of pitch. First, all utterances of the corpus are segmented into phoneme sequences by forced alignment. Meanwhile, labelling of utterance with two prosodic tags of break and prosodic state is performed by the PLM algorithm proposed previously. Then, the influences of linguistic features and prosodic tags on the three prosodic-acoustic features are analyzed. The method of regression tree is employed to determine the estimates of these three prosodic-acoustic features in different contexts considering various combinations of linguistic features and prosodic tags. Experimental results show that the proposed method can improve the syntheses of these three prosodic-acoustic features.