Yeah getting ready to crow sounds like. Some birdies have kind of a cock-a-ah-ah sound at first. Just keep an eye on them, if that's the only thing they're doing they sound just normal.
Good luck and keep us updated, especially if anything changes.
Could be they are getting ready to crow.
However, I've noticed my hens do this from time to time even when they were little chicks. We thought that our barred rock was choking the first time and really freaked out, however, it doesn't seem to harm them. I think they do it sometimes just to...