Inhaled seek husks or other bits of debris can cause this. When getting feeds with lots of loose husks I wet them down to prevent this. Also some chooks go nuts over millets and other tiny seeds and scoff them so eagerly that they end up inhaling some, another common cause of squeaking.
Generally, they should be fine without any intervention; almost all are, even when they sound absolutely terrible (a Light Sussex hen I had was braying like a demented donkey for a bit, with every single breath, thought she'd die but I still have her years later... She fixed up within a few days)... But if her face begins going blue, best to put her down. I had another hen inhale something and this one got worse and worse until it was clear she was dying, so she received a mercy kill. And another hen inhaled some grass and died, once; if she hadn't been trying to scream at me and swallow grass at the same time she'd have been fine. Her aggression did her in, lol...
Asides from that I've had many chooks inhale something and most manage to squeak it out with three or less squeaks, lol, only those three cases ever went longer, and since giving them soaked feeds the problem is pretty much nonexistent. Very rarely happens.
There's a chance it's a disease of course but it doesn't sound like it to me, sounds more typical for having inhaled something that's gotten stuck.
Good luck with it, and best wishes.
