Polish spelling is quite regular and has almost one-to-one sound-grapheme correspondence. C not before i or z is always /ts/.
Right, I will report the audio when I get this sentence next time then, since I can't hear any t
Because there isn't any /t/.
/ts/ is a single sound and the audio is fine.
Try saying "miesiąs" over and over again, in your best Polish accent - I'm willing to bet that you can't make the /s/ sound, and that it'll keep coming out as a /ts/. Once you become more comfortable with the phonology, the spelling rules will start to feel a lot more innate!
Mouse over Tydzień. Not sure if that's some new thing called speed-polish or something.
Maybe it's only for me? But the audio is extremely fast. Don't say it's actaully how you say it haha. Though, what is weird is when the woman says all three after eachother with the Repeat-button, it's lot slower speed. I sent report, I won't clutter here :)