语音识别中基于语谱图 的语音音素分割方法

语谱 图在语音分析方 面 有着广泛 的应用.音素的 自动分割是语音识别过程中的一个基本阶段,它 将把语音句子按音素特征 进行分割.本文提出 了一 个音素 自动分割的方法 ;使用了两个表示 语谱图密度变化 的形变函 数,以及 自适应阂值技术来 定位每个音素段的边 缘.这个方法在 计算机 上 具体实现 后.我们对取于 一 个 语谱图数据 库的一组 实验数据,用本 文所介绍 的自动分割方法划分 音素,将所得结果与 由一 语音学家分 割的结果进行 比较,得到 的识别率高于 93 %.这 个方法作为语音识别系 统的一 部分.已经在一 个语音分析 系统中使用.

A Method of Automatic Segmentation for Speech Recognition Based on Spectrograms

A spectrogram is a grey scale image, which represents the energy changes of a speech signal. Automatic segmentation is an initial phase in the acoustic-phonetic analysis of automatic speech recognition based on spectrograms. Speech segmentation can be defined as the process of dividing the spectrogram into a sequence of segments, each segment indicating phonemic characteristics. This paper presents a method of automatic segmentation with image processing techniques. We describe two special functions which indicate the intensity changes of the spectrograms called. Together with these two functions, we used adaptive threshold techniques to detect the location of the edges for each segment. The threshold was calculated based on an optimum relation equation which was defined using interpolating linear nulti-ple regression. After the preliminary segmentation, a segmentation check procedure was taken to check the segmentation results. The algorithm was evaluated by comparing the automatic segmentation result with another segmentation result carried out by a phonetic expert. This automatic segmentation facility is a part of an automatic feature extraction program appiled in a speech analysis system.