English vowels have several pronounciations so when people try to explain how to pronounce foreign words (without IPA, which is what they should be using ;-)) they add lots of silent Hs and hyphens, e.g. KAH-zah.
Problem is, as a non-native speaker this only adds to the confusion. What's the meaning of those Hs at the end of syllables? Do they make the vowels short or long? In "uh-oh", they seem to do both (it sounds as /oʔoʊ/ to me).
Could someone use IPA to explain how "ah, eh, ih, oh, uh" sound and tell me how they differ from "a, e, i, o, u" that make people feel the need to add an H?