Acoustic Resonance Test

I examined an empty metal bottle cap resting upside down beneath the park bench. A dried maple seed pod lay angled across its serrated rim. Testing the fulcrum, I stepped onto the flat tip of the seed pod's wing. The lever depressed, tapping the crimped metal edge against the paving with a crisp click. By alternating downward pressure between my left and right foot joints, I sustained a measured percussion against the concrete. The hollow chamber beneath the wooden bench amplified each frequency cleanly. Vibration transfer was consistent.