Basic features such as formant frequencies were extracted and
grouped according to vowels. This research provided the
first analysis of Thai phonemes using a large real-speech
corpus, not just a small set of sample utterances. There is
still a lack of sufficient research on prosody analysis for
Thai, however data collection is not a trivial task, and thus
research on prosody modeling has been substantially
delayed. Since 2000, research on basic linguistic features
has decreased and the engineering of high-level speech
applications such as speech recognition and synthesis has
taken priority.