Long vowel reduction in the Mongolian Language
In Mongolian, the phenomenon of vowel reduction is notably active. Although phonologists have done a lot of research on short vowel reductions, experimental phonetic studies on reductions of long vowels which are independent phonemes responsible for distinguishing meanings in Mongolian, are rare. Therefore, this paper aims to study the long vowel reductions of the Mongolian language using experimental methods (acoustic phonetic method). Vowel reduction is detected with its formant and length.
Firstly, the long vowel reduction in Mongolian language is weak compared to the short vowel reduction. Secondly, long vowels can appear in the first, second, and third syllables of a word in sequences. For example, [xe:ke:re:]-хээгээрээ, [tsha:na:sa:]-цаанаасаа, [thɔ:tshɔ:kɔ:]-тооцоогоо, [ʊ:kʊ:rʊ:]-өөгөөрөө. Long vowels in the first, second, and third syllables of a three-syllable word differ in their sound formant. The degree of long vowel reduction is characterized by the order of the first, second, and third syllables.
However, in two-syllable words, the long vowels of the last syllable are reduced from the one of the first syllable in such a way that they end up to the center of tongue. The mid-high, front long vowel / e: / ‘ee, and the mid-high, middle long vowel / ʊ: / ‘өө’ are reduced by the p-value.
The low and middle long vowel /а:/ ‘аа’ is reduced by p-value of F1 while the mid-low, back long vowel /ɔ:/ ‘оо’ is reduced by p-value of F2.
In comparison of long vowels in the middle (of the second syllable) of words that differ in the presence of short and long vowels in the front and back syllables of a three-syllable word, and long vowels in the middle (of the second syllable) of words with only long vowels, differ in their formants.
As for the length of the long vowel, there was no difference in p-value between the length of the long vowel in the first syllable before the short vowel and the length of the long vowel in the second syllable after the short vowel of the two-syllable words. This can be explained that long vowels of the first syllables of words are pronounced long whereas, long vowels of the second syllables are pronounced at their length because open syllables extend at the end of words.
When long vowels occur in the 1st, 2nd, and 3rd syllables of a word in sequence, all long vowels except the long vowel / a: / are the longest in the first syllable, and the shortest in the second syllable in the p-value. At the same time, as we compare the long vowels in the first syllable of a two-syllable word, the second syllable of a two-syllable word, and the second syllable of a three-syllable word that are not in sequences in the same word, the long vowel of the second syllable of three-syllable word is shorter than the ones of the 1st and 2nd syllables of a two-syllable word in the p-value. This means that long vowels in the second syllable of a word with more than 3 syllables are reduced regardless of whether they occur in sequences in the word or not.
We hope that the results of this study will be the basis for a long vowel study of the Mongolian language, as well as an experimental phonetic material for the Mongolian language, which will contribute to mother tongue education and the teaching of Mongolian to foreigners.