The audio should say "sang" as in sung, not seng.
Does sang really juse mean "the"? Like the suffix -nya in some cases? Is it only used when talking about people from royal families?
Not just for royalty, but it is a term of respect. You could also use it to when speaking a flag or of a respected teacher. Something like "the esteemed" or "the honourable".
My understanding was that "sang" was an article roughly translating to "the aforementioned", as in, a person you have already mentioned in the context of the conversation. But I could be wrong, I only learned this from observation.