First time chicken owner. I have a 10-wk-old Easter Egger pullet (yes, I'm 95% sure she is female, won't be 100% until I see that first egg) who is very vocal and has been "beeping" at me since she was tiny. Yesterday, her "beep" sounded more like a "honk" ... deeper and squeakier. Occasionally, it would sound "normal" again, then would go back to sounding odd. She seems fine. Activity and appetite all good. Drinking normally. Nutmeg (pullet in question) is my most active chicken and runs around all the time. This hasn't changed. No nasal or ocular discharge, no difficulty breathing. Crop feels normal. Poop appears normal. She had one incidence of gaping (not panting) a couple days ago, during a major heat wave, but nothing since. All the chickens sneeze on occasion, but nothing chronic or persistent. I did a fecal float to check for parasites, gapeworm in particular, and found nothing even remotely suspicious. This morning, she still seems fine, but her "voice" continues to sound strange. I have two cockerels in addition to my 10 pullets and I have noticed distinct differences in the sounds they make as they've gotten older (no crowing yet though), but until now the pullets have all sounded pretty much the same as before. Nutmeg is not my oldest pullet and I thought EEs matured more slowly, yet she is the only one who's voice has noticeably changed. She is, however, my most vocal bird and she talks to me more than the other chickens, which may be why I've noticed a change in her but not the rest. Could it be that this girl is hitting puberty, causing the change in her voice? Is this a thing? If it's not a puberty thing, what might it be? Should I be worried and keep looking for some underlying cause?