A question about duck eggs

I believe one of my duckies is about to hatch. First time I've ever incubated duck eggs. The air pocket has gotten pretty big but I read that you should hear them making noise just before hatching?? It's day 25 or 26 so I know the little guy is about ready to leave his shell. Anyway I guess I'm hung up on the noise thing, as I don't know if: A) That's always the case B) Does it mean they're not healthy if you don't hear little chirps? Like I said I'm new to this, so forgive me if I sound ignorant. Thanks for any help.

Hi Mia, I'm just now seeing your post. How did your hatch go?

Well, the first little guy didn't survive. The rest though are doing very well. Getting bigger everyday