these are the sounds found in most native Thai dialects:
there are also sounds not on the chart

Other sounds:

labio-velar central approximant [w]
aspirated voiceless stops
unaspirated and aspirated voiceless alveolo-palatal affricate
three dipthongs (first segment = one of the three high vowels, second segment = low vowel)

(from: Handbook of the International Phonetic Association. 1999. Cambridge. Cambridge University Press.)