<ฑ> Tho-Montho from 10 Thai dictionaries

Abstract

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.