You can get the most of the mantras, aartis, and chalisas when you pronounce them properly. This is particularly true for mantras when you want to get the most of it. We therefore have tried to follow the vowel pronunciation key below as much as possible on this site.

a: as "u" in "but"
aa: as "a" in "far"
e: as "e" in "bed"
i: as "i" in "fit"
ee: as "ee" in "feet"
o: as "o" in "code"
u: as "u" in "put"
oo: as "oo" in "pool"
au: as "ow" in "how"
ai: as "ei" in "neighbour"