hmm..wel...i see "hieh" as 嘿 ~ just like something you end up with one sentence..
some ppl use la...ba...behh....le..lo....somthing like that i suppose...heih~ ...
i dun really know what it means now..just happen to type it out whenever i finish some words..it is like.....反射動作~ heih~ ....it doesnt mean anything bad lo....so ..eh....sorry if that doesnt make you feel comfortable...i try my best not to use it then~ h..... almost type it out again..~ >< ...