Anyway, here's more (and I am aware I have mentioned rocks elsewhere here and will do so again in the future, it's just one of my things.)
The Brantwood Musical Stones PDF
They sound rather like humming ringwraith!
K, so that had nothing to do with a tree falling but everything to do with sound itself.
'If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.'
― Nikola Tesla