'I know/knew "din" approximates to "noise", but feel that it is rather to strong a word; that is, unless she had tackety boots on and was tap-dancing, "din" isn't the word which I'd use naturally for "sound of footsteps", and it therefore seems a forced word, chosen for its rhyme with the simple "in"' ...

Trad. songs and faux-trad. songs are full of words which are peculiar to some or all modern listeners because they are archaic, denote archaic meanings, are faux-archaic, dialectal, faux-dialectal, artificially 'poetic', or some combination of the preceding. I don't know which of these apply to the word 'din' in this song, but to my ear, that word has a tone (so to speak) consistent with that of the rest of the diction of the song. The cumulative effect of this archaic-poetic diction, like that of the diction of the King James Bible, is to place the story in a world that is strange and charming, at the same time that it is familiar. If, like me, you ignore the interpretation of the song that gives it TB and infection and ghosties and hocus-pocus, then a simple expression of erotic longing comes through somehow all the more powerfully because of the slightly-jarring diction. In other words, the contrast between the unfamiliarity of the diction, on the one hand, and the familiarity of a universal human passion, on the other, makes the effect all the more striking.