I read a write up on some conspiratorial website years ago. But the guy seemed like a credible acoustician based on the technicality of the write up. He claimed to have brought a signal generator and speaker and microphones in and measured the response of the inside of the great pyramid in different locations. He discovered that one of the "escape hatches" happened to resonate at a specific frequency, it was basically tuned seemingly on purpose. And when the wind blows across the hole on the outside, it resonates and makes a noise at that frequency. Like blowing across the top of a partially full soda bottle. Not sure where to find that info nowadays, I may have it saved somewhere.