<P> There was a two - way voiced vs. voiceless distinction among all fricative and sonorant consonants, and up to a four - way distinction among stops and affricates . The maximal four - way occurred in labials (/ p ph b ʔb /) and dentals (/ t th d ʔd /); the three - way distinction among velars (/ k kh ɡ /) and palatals (/ tɕ tɕh dʑ /), with the glottalized member of each set apparently missing . </P> <P> The major change between old and modern Thai was due to voicing distinction losses and the concomitant tone split . This may have happened between about 1300 and 1600 CE, possibly occurring at different times in different parts of the Thai - speaking area . All voiced--voiceless pairs of consonants lost the voicing distinction: </P> <Ul> <Li> Plain voiced stops (/ bd ɡ dʑ /) became voiceless aspirated stops (/ ph th kh tɕh /). </Li> <Li> Voiced fricatives became voiceless . </Li> <Li> Voiceless sonorants became voiced . </Li> </Ul> <Li> Plain voiced stops (/ bd ɡ dʑ /) became voiceless aspirated stops (/ ph th kh tɕh /). </Li>

In what country is thai spoken by 92 of the population