Strange noises.....
I've already discussed Remi the wonder-groaner, who groans in conversation.
My Gaci has a wide range of noises. She too often "yips" when she yawns. It's not too loud, but high pitched. She also usually only does it after "happy" yawns, like waking up in the morning, waking up after a nap, excited to go for a walk, etc. Not during stress yawns. She also talks back to me. Sometimes if I tell here something is "Mine", or to get "off", she'll talk back in some sort of whine/woo-woo/thing. Reminds me of a teenager mumbling when a parent chastises it.
Kamara is the queen of conversation, daughter to the famous Remi-grunter. She woo's, waaa's, whines, screams (at other dogs mostly), and also has entire conversations..minus the grunts. You know her when you hear her.
Some of our guys do the "backwards sneeze" thing, I think that's what you are referring to with your Chi's?
You also are prone to hear the "Schnauzer chorus" if you're at our house at least once daily. This is the synchronized, opera-worthy howling of 12 Schnauzers baying/wooing/howling in unison. They have their own octaves, pitch, and timing, to make a beautiful song. Tends to be heard best at daybreak or dusk, with occasional mid-day turns if there is something particular exciting going on. Relegated to outdoors only.