<ฑ> Tho-Montho from 10 Thai dictionaries

                This paper studies the source and sound development of <ฑ> Tho-Montho and its variants, [th] and [d] from 10 Thai Dictionaries. The analysis and discussion are based on historical linguistics, phonetics, phonology and statistics. The results show that the sound of <ฑ> is developed from two phonemes in Pali and Sanskrit, a voiced retroflex stop /ɖ/ of the Devanagari alphabet <ड> and a voiced dental stop /ɖ/ of the Devanagari alphabet <द>. From all possible occurrences in Thai, the grapheme <ฑ> is mostly pronounced with a voiceless aspirated alveolar stop [th] as high as 46.04 % at sysllable initial position and pronounced with a voiced alveolar stop [d] 15.79 % also at sysllable initial position. The ratio of [th] to [d] is approximately 3:1 at sysllable initial position. The grapheme <ฑ> which is pronounced [th] can be divided into 2 groups; 1) The development of [th] for <ฑ> in the same manner of [th] for <ท> from loanwords and Grimm’s Law where voiced phonemes becomes voiceless and further aspirated. 2) The prescription of the Thai Dictionary Rattanakosin era 120 by the official language Institute and/or the educational department. The grapheme <ฑ> which is pronounced [d] can also be divided into 2 groups; 1) Those as residue of historical form with evidence of the letters <ด> and <ฎ> used in older the dictionaries prior to revision where <ฑ> was used instead. 2) Those prescribed by the official language Institute and/or educational department. However, the phonetic environment for the variants of [th] and [d] cannot be found neither in vowels nor syllable structure.

Credit :  กมลชนก ธรรมมิกะ // อภิลักษณ์ ธรรมทวีธิกุล

https://so05.tci-thaijo.org/index.php/irdssru/article/view/214156