10.5937/specedreh13-6038 = Maximal vowel space method in analysis of vowels in prelingual speech phase

Abstract

e main problems in the analysis of vowels which occur in prelingual speech phase are centralization of utterance and unknown dimension of vocal tract. Most researches in this eld are based on the analysis of maximal vowel space (MVS) because discrimination of vowels is very di cult in this early period. MVS analysis includes the estimation of vocal tract (VT) physical dimensions. e aim of this research was to estimate and de ne changes in vowel pronunciation during prelingual speech phase. e analysis and voice recording were performed in a two month old child until he turned one. e recording was performed in 42 sessions, on average 4 sessions every month. Sound segments that look like vowel pronunciation were extracted from the recordings and were used for the formant frequencies estimation by PRAAT so ware. e Burg method was used for formant frequency estimation. Research results showed that MVS can be used in diagnostic procedure from a child's earliest age. MVS analysis is appropriate for a child's earliest age as a child needs to pronounce individual phonemes, and does not need to respond to speech stimuli. ese results need to be con rmed on a larger sample when extended analysis should de ne criteria for discrimination of typical and atypical formant frequencies.