Sound waves with frequencies higher than the upper audible limit of human hearing, typically above 20 kHz.
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Ditelluride, bis(phenylmethyl)
Benzene, 1-(2-fluoroethenyl)-4-methyl-, (E)-
3,5-bis(4-(trifluoromethyl)phenyl)-1,2,4-thiadiazole
3,8-Dimethyl-3,8-diphenyl-2,7-dioxaspiro<4.4>nonane-1,6-dione
