Sounds in the videos are loaded with meaning. The pulsed unh-unh-uhh is a low intensity agression vocalization. Hens are telling you to back off. If more aggressive, then greater emphasis will come in the h-parts of syllables above, wings will be positioned at a 45 degree angle down from the relaxed position and tail will be fanned out. Those are talking a lot more than we give them credit for. The sneezing / whistle is as indicated above an attempt to clean air passages.