I'm not sure what it's called in Irish, if it even has a term, but I know that the separation between the two that you see is defined by something that's called a palatalization. It's difficult to explain in words, at least for me, so I'd suggest looking it up and hearing different samples to understand the phonetic separation. I'm not sure of the exact history as to why this is in Irish, but it represents the pluralitization of a word. Though, from what I can tell it depends on the kind of word or phrase. Someone correct me if I'm otherwise wrong.
I see that "ball" is "member" and "baill" is members. Tell me they are pronounced differently. I remember she pronounces "cailleann" like the name Colin so I'm figuring "baill" is the same [awl] sound, but if I was to guess, I would have thought "ball" would be pronounced [bahl] like "pal" and "Mal(colm)".