Sounds like a crow to me. The chicken in the front in the 3rd picture has longer tail feathers, the comb is a darker red & slightly bigger (not by much). Maybe he's a late bloomer??? But what do I know, I've only had chickens for only 1 1/2 yrs. My cockerel started to crow at 8wks & it sounded like he was being strangled. It took a few days & then he wouldn't shut up. Had to rehome him as I can't have roosters in the city.
Sounds like crowing to me.
If those are the only two chickens you have, and if your neighbors do not have chickens, then I think one of your two is a cockerel.
(If they both lay eggs in the future, do come tell me I'm wrong. In this case, I'd love to be wrong!)
Some Pullets do crow, i read somewhere when there are no roo's around, a pullet will take over the flock instead. Could also be hormonal imbalances someone said in a previous post. Or she saw something potentionally dangerous and made that sound as a warning.
You can find a lot more on the internet about this.