The audio is wrong actually. Both should be -atun at the end for grammatical reasons.
The sound of -(v)N at the end of words (where "v" stands for a vowel), is called Tanwin or Nunation. Long history short, when a word is indefinite (i.e. has no AL in its beginning), nunation can be considered as a sign of indefinite word. As to why there is (t) in both of them, this is because they are feminine adjectives describing Lamá (a female's name), and hence they end in Ta-Marbúta (ة) which is a letter used mostly for feminine nouns and adjectives and in normal conditions it sounds like H, but when moved with vowels it turns to T.