When I was in Vietnam I tried to pronounce the word mười (10) with the Thai/Lao/Khmer uu sound:

Thai: ◌ู
Lao: enter image description here
Khmer (ou):
Khmer (uə):

I recognized that sometimes it worked and sometimes it didn't and at some point assumed that either it is indeed shared but I'm wrong somewhere else, or that the Vietnamese uu sound is a bit different than that of Thai/Lao/Khmer.

Does Vietnamese "uu" in mười reflects the Thai/Lao/Khmer uu sound or is it something similar but essentially different so that it doesn't exist in Thai/Lao/Khmer at all?

2 Answers 2


Short answer

The Thai vowel อู is a high, back, rounded vowel.
The corresponding Lao vowel is very similar and for the Khmer one I can’t comment.

The first element of the Vietnamese diphthong in mười is the vowel ư, which is a high, central, unrounded vowel.

Vietnamese also has a vowel u, which is like อู is a high back rounded vowel.

Interim summary

The vowel ư in mười is essentially different from อู in that it is unrounded.
If anything, u would correspond to อู instead.

Long answer (based on short answer)

The sample formant values shown in the below paint, indicate a slightly more complex picture:

อู u ư

F1  1417.62           470                380

F2  918.76            760               1390

F3  2776.98          2690           2870

These values put อู somewhere between ư, and u, though quite a bit closer to u.
I think it's still fair to say that there is an essential difference between อู and ư, in that one is rounded and the other is not.
The take-away is really that อู is not exactly the same as u either.
On a practical level, if you use it in place of ư, it is likely to be heard as u, or at the very least, you will have a hard time making a distinction between ư and u.

Sources of the formant values (and the qualitative descriptions of the vowels):

Thai: Directly reported in Narang and Misra, Acoustic Space, Duration and Formant Patterns in vowels of Bangkok Thai, Language Processing 20(3) 123.

Vietnamese: Via Praat from the native-speaker examples in the pronunciation guide in Bin Nhu Ngo, Elementary Vietnamese, Tuttle 2015 (based on Hanoi Vietnamese).


I would post this as a comment but I don't have the rep. If you look on YT you will find a series called Sawasdee Vietnam which teaches Vietnamese in Thai. You might find that helpful if you are interested in correspondences between the sounds (I think episode 2 goes through the vowels). I'm fairly sure ư gets equated with with อือ. I'm a lot less sure that's accurate, but it does tell you that Thai speakers aren't hearing อู. I don't think there's any lip-rounding going on in ư.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.