What this is
The ratios are exact: a just fifth is 3:2 (701.96 cents), which is ~2 cents wider than the equal-tempered fifth (700 cents) — that tiny gap is the beat you hear when you add the twin. Chladni figures are real nodal patterns of a vibrating plate (Chladni 1787); the mode numbers here are an illustration of the ratio, not a claim about any particular plate.
No healing claims — just arithmetic you can hear. Listen at a gentle volume.