in·au·di·ble 
/ɪnˈɑ:dəbəl/ adjective
/ɪnˈɑ:dəbəl/ adjective : impossible to hear : not audible
▪ She spoke so quietly that she was almost inaudible. ▪ The sound is inaudible to humans but can be heard by dogs.
▪ She spoke so quietly that she was almost inaudible. ▪ The sound is inaudible to humans but can be heard by dogs.
— in·au·di·bil·i·ty /ɪnˌɑ:dəˈbɪləti/ noun [noncount]
/ɪnˌɑ:dəˈbɪləti/ noun [noncount]— in·au·di·bly /ɪnˈɑ:dəbli/ adverb
▪ He whispered inaudibly to the person beside him.
/ɪnˈɑ:dəbli/ adverb ▪ He whispered inaudibly to the person beside him.
