I couldn't get the sneeze on video,but would you be concerned about my Easter Eggers quiet chirping? She acts normally otherwise, except some occasional sneezing. She's 2.5 weeks old.
I've had chicks make some strange sounds, but nothing quite like that. However, she appears alert and active. I don't see any nasal discharge and her eyes are clear. I wouldn't worry. Sneezing is normal, chicks/chickens bathe in the dirt, sneezes just come with the territory. The sneezes become a concern when they're accompanied by yucky things like runny eyes and noses.
Your silkie on your profile picture is amazing! What color is s/he? I just got white ones ( and some mille fleur d'Uccles)- first time owning chickens! :-D