When I was bothering to watch DS on Sci Fi (when available) a couple of runs back, mainly because I didn't yet have most of the shows on tape, I remember muffled sound frequently on Sci Fi's broadcasts of DS, not just for this month of 1897.
I also have noticed on the MPI tapes episodes where some other soundtrack was playing behind the existing soundtrack. There's an episode from the 1968 storyline when Julia comes staggering in from Tom's feast in the woods where my MPI tape has a jarring, harsh noise that lasts a couple of seconds. Richard Holt said this was on the master tape. And then there are all of those shows where one of the cameras seemed to have some kind of weird fisheye lens on it and nobody bothered to fix it!
I guess we can just count our blessings that so much of the show survives and looks and sounds as good as it does. If you want comparisons, try another mid Sixties soap. I have 5 shows from the 1966 Days of Our Lives and it's soooo dull.
Gothick