Vientiane tones according to Osatananda (1997, p. 66)
Number
Name
Chao letters
Example
1
mid level
33
ຄ່າ
2
low
1(3)
ຂາ
3
high
35
ຄາ
4
high-fall
52
ຄ້າ
5
mid-fall
31
ຂ້າ
Vientiane tones according to Osatananda (1997, p. 40)
ຜາ 1(3)
ຜ່າ 33
ຜ້າ 31
ຜາກ 31
ຜັກ 35
ປາ 1(3)
ປ່າ 33
ປ້າ 52
ປາກ 31
ປັກ 35
ບາ 1(3)
ບ່າ 33
ບ້າ 52
ບາກ 31
ບັກ 35
ພາ 35
ພ່າ 33
ພ້າ 52
ພາກ 52
ພັກ 33
"Tonal Alternation for Low Tone"
About the low tone (e.g., ກາ and ຂາ): "A low tone usually preserves its rising contour shape before a pause. Otherwise, the rise is not realized. This process applies before all major syntactic boundaries."
Osatananda, V (2015). Lao Khrang and Luang Phrabang Lao: A comparison of tonal systems and foreign-accent rating by Luang Phrabang judges. The Journal of Lao Studies, Special Issue 2, 110-143. http://www.laostudies.org/system/files/subscription/Varisa.pdf
You might find more research studies when you use the names of researchers in Thai. Varisa Osatananda is วริษา โอสถานนท์, and Phinnarat Akharawatthanakun is พิณรัตน์ อัครวัฒนากุล.
