Isn’t this as simple as "the piezoelectric effect works in both directions"? If you pump enough wattage through a dummy load (large resisters), they will play music at a very low volume. That effect is small, but multiply it by all the components in your chain. I believe this may be important in a high end system, but it’s the last thing on my list to dive deeply into because it’s complicated and requires a lot of trial and error and a good system. And microphonics are another reason I avoid tubes. I just bought my first Shatki Air Stone and liked it enough to buy another. Some of it’s effect may be mechanical since it’s heavy like a small stone and has a rubber coupling mat on the bottom. There’s enough reviewers agreeing on the importance of vibration control and tuning that it seems worth a little trial and error. The Cable Company has served me well recently and they have a wide variety of products.
I loved the AI quote, here’s another one from Claude 3.5, aren’t all conductors crystals a sort of crystal? Also think about the clock crystals in your digital gear.