inaudible

[adj] - impossible to hear
Found on http://www.webdictionary.co.uk/definition.php?query=inaudible

Inaudible

In·au'di·ble adjective [ Latin inaudibilis ; prefix in- not + audire to hear: confer French unaudible . See In- not, and Audible .] Not audible; incapable of being heard; silent. -- In*au'di*ble*ness , noun -- In*au'di...
Found on http://www.encyclo.co.uk/webster/I/28

inaudible

unhearable adjective impossible to hear; imperceptible by the ear; `an inaudible conversation`
Found on https://www.encyclo.co.uk/local/20974

Inaudible

• (a.) Not audible; incapable of being heard; silent.
Found on http://thinkexist.com/dictionary/meaning/inaudible/

inaudible

inaudible Not loud enough to be heard; unhearable.
Found on http://www.wordinfo.info/words/index/info/view_unit/248/5

inaudible

impossible to hear; imperceptible by the ear
Found on https://www.vocabulary.com/lists/437324
No exact match found