Quote Originally Posted by riku View Post
You are close but not quite there. As long as the speed of exiting air remains subsonic the difference in flow speed causes the dB peak to shift up or down in frequency. Higher speed (small exit hole) makes the peak a bit louder in dB scale but also moves it up in frequency which is why many consider it quieter.
Like a pan pipe or any wind instruments.... Shorter tube (smaller hole) is higher note???