well, that is a good description of the noise, never thought to describe it that way. I heard it while at a park in Upstate New York about 3 weeks ago. Went on for about 20 minutes. I've told about it before, but I still can't believe - I was at the park again Sunday and everything was same as it's been for years. Quiet except when there are kids playing. But 3 weeks ago? FREAKIN' loud pulsating overwhelming sound coming at me from the sky while everything was bathed in a pink sunset! My dog didn't react because sometime we take her to the airport and she's used to hearing a 747 take off. (Park is nowhere near airport though).