The physics behind human whistling--where does the sound come from? In most whistles, air is split somehow. When humans whistle (by forming a small hole with their lips), this is definitely not the case. I would assume that the mouth is the resonance chamber because pitch can be altered by moving the tongue, palate, etc. However, our mouths are open at BOTH ends. And we can whistle by both exhaling and inhaling. How is it possible that blowing air OUT of our mouths could create enough vibration that then resonates INSIDE out mouths? What is creating the whistling sound, and where, and how?