inaudible
/aɪˈnɔɪdɪbəl/Definitions
1. adjective
unable to be heard; too faint to be perceived by the ear
“The inaudible humming of the refrigerator was a nuisance in the quiet room.”
2. noun
a sound that is too faint to be heard
“The inaudible whisper was barely audible over the background noise.”