Separating phonetic and speaker features of vowels in formant space

Phonetic components of vocalic segments are primarily contained in the three lowest formants in speech signals. However, different vocal tracts and speaking habits do show formant pattern differences for different speakers. This study intends to analyze or to separate phonetic and speaker characteristics into a set of orthogonal dimensions. Statistical analysis by a linear transformation of the principle components in the three-formant space is the basis of the study. Experiments on the vocalic segments of a conversational database, and vowel portions of specific digits in a connected digit database are reported. Experimental recognition results and a statistical interpretation are presented. Comparison with a vowel space model is also investigated. It is shown that the distribution of vowels in eigenvector space can be used for speaker identification.