What is another word for "inaudible"?

Roget's Thesaurus (1911) lists these synonyms for "inaudible": absence, adder, all, and, any, aphonia, aphonous, aphony, awful, bated, beetle, better, breath, breathless, broken, childish, close, could, cracked, cut, dead, deaf, deaf-mute, deafen, deafness, deathlike, doubt, drop, drown, dry, dull, dumb, dumbness, dumfounder, dummy, dysphony, ear, earless, est, evil.