To me:
1) Isan would be pronounced short I, SAN.
2) Issan, I as long E, (why I don't know, could be short I sound as well) drawn out double S sound, then AN.
3) Isaan, IS as 'is', drawn out double A, then N.
Pete

The a in can't is a short vowel sound.Bamboo Grove wrote:English language knows no difference between short and long vowels and this is were the problem starts. I would go for option 3 as the "a" is a long vowel like in the English word "can't" pronounced in English accent.