Jonáš Gruska: “I was recording this guy last night in high sample rate. What interests me is how seemingly uniformly sounding pattern hides variations only visible through the spectral examination (or at least I couldn’t tell there was so much changes in the sound).
Listen to the 15 seconds of the pictured sound and then ~17.5 slower version of the same sound.“
… further links: jg, lom, Chočské vrchy a doliny, Fontána