Loud? Expand perspectives: audio frequencies can be broadcast through the plasma spectrum of light. No sound per se.
https://www.thegb4000.com/
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Effectiveness? Review Dr. Rife's story. Peer reviewed, 18 stage 4 cancer patients, all cured. When it was disclosed that parasites were the cause, his equipment, lab notes confiscated and license to practice medicine revoked. Financially destroyed.