IPA: /ˈsaʊndləs/
KK: /ˈsaʊndləs/
Not producing any noise or sound.
The soundless room made it easy to concentrate on my work.
Soundless → It is formed from "sound" (from Old English "sund", meaning noise or auditory sensation) and "-less" (meaning without). The word "soundless" means without sound or silent.
Think of being 'without' ('-less') any 'noise' ('sound') — that's why soundless means silent.