It is dusk and a bear is heading straight towards me. The wind is weak and in my direction so I stand completely still and enjoy being invisible. It's awesome! When I think that the distance is close enough, I move the camera from side to side a few times whereupon the bear stops immediately.
Since it is not aware my scent it becomes insecure, what am I, friend or foe? It sweeps back and forth with its nose but got no answer. The bear blowing the air out through its nose with immense strength, as if trying to clear it and a loud whistle arise. This is repeated a few times. I have often heard about the bear whistling sound, but it's the first time I experienced it.
It get for me to pretend to be another larger bear so I imitates with all the power I can muster its whistling by pressing the air stream between the teeth, and I succeed! It gets really frightened, throwing aside and rushes then up a slope where it stops for a moment and look at me. What an experience! It really strengthened my male ego :-)