Native dutch from the eastern part that has lived in the southern part too, now in Munich and knows (and speaks) quite a lot of dialects. This sounds like someone from Luxemburg would be better at understanding. It's a mixture of dutch spoken in Limburg (soft tones, not the "hard" r and g pronounciation that is typical for the western parts of the Netherlands) but also not that modern vlaams melody. I could understand it roundabout a sgood as when I hear someone speaking Afrikaans.

If it's any help, I speak pretty good dutch, some german, and some czech (which is similar to polish) and can only understand about 1/4 of this. Any native dutch speakers can feel free to chime in, but I don't think speaking dutch is a major advantage in understanding this.

Native Dutch here. I agree. I understand some words that are more like numbers in German but nothing much else.

I speak (Austrian) German and it sounds a lot more like a German dialect than Dutch to me (there are so many of them, though, this is not really saying an awful lot). Like the Dutch speakers who've chimed in, I don't understand much of it but can pick out enough words to tell where the other, incomprehensible words are.

I agree, I have no idea how to pronounce the words unfortunately, but lots of it resembles bavarian, or even allemanic dialect.

E.g. "s’błimła (‘flower’)" - "s'Blüamle" (allemanic)

Obviously this comparison would benefit from using a phonetic scripture.

At first I thought it was related to yiddish...

Having listened to the above youtube video, I think resemblance to allemanic might be coincidental, as it is so often.

Judging from the pronunciation, I would also put some "idioms" of this dialect in Dutch/Flemish regions (there is maybe a distinct polish influence in there that throws one off?).

As so often for me, the written word it seems is way more understandable than the spoken word. I had the same experience with Swedish. Weird how some languages kept similarities in writing longer than similar pronunciation.

There are also a lot of strange tricks personal perception and familiarity play on you. I found this easier to listen to first and then listen and look at the text together later. I similarly find myself thrown for a loop whenever I see Viennese/Bavarian written. 'Wir sind' - easy to read and hear, 'mia san' easily matches up with the former when heard. 'Mia san' written down and for a moment I have no idea what I'm looking at. Feels weird to even type it out.

German influence. Before ~1918 area was a part of German language 'island' of Bielitz. A town nearby called Hałcnów had a similar local language that was much more similar to German.

It sounds like some Dutch farmer dialects. I cannot understand a word of it, but it surely does not sound anything like a slavic language to me.

The first fragment with the old woman sounds a bit more like Dutch or Low Saxon but with heavy German influence. The second clip with the young man sounds very much like a German dialect to me (Dutch native). Understanding either of them completely would take a lot of effort.

Sounded like "1+1 am Tag macht 2" at 4:33

2nd video: "Das sind die Sproech" "Da kann ich gehn, da kann ich meditieren, da kann ich alles machen" almost plain German. at 0:44 - 1:00

and many other German snippets

Afrikaans speaker here. Might as well have been Russian. Didn't get any of it.