Yes, I skipped the text at first and wanting to see what this sine wave speech sounded like just clicked on the first sample. I understood all but a word or two on the first play through. After reading the text I seem to do about the same on the other samples as well.

Interestingly for me, although standard hearing tests show I have good hearing (somewhat above average for my age despite experiencing minor tinnitus) I seem to be worse than normal at understanding speech in noisy environments (e.g. near loud engines).

Yes, but only after 2-3 listens.

Yes, except one word. But I'm not a native speaker.

Yes