Very tangential, but your comment reminded me of this... I have this weird trick where I can put the back of my tongue against the roof of my mouth, and exhale

Very tangential, but your comment reminded me of this... I have this weird trick where I can put the back of my tongue against the roof of my mouth, and exhale I'm a certain way that causes a whistling sound, I think where my sinuses reach my throat. That often makes me light-headed very shortly after for some reason.