unhearable
1. [ adjective ] impossible to hear; imperceptible by the ear
Synonyms: inaudible
Examples:

"an inaudible conversation"

Related terms: audible supersonic silent infrasonic unheard silent breathed quiet imperceptible audibility
Similar spelling:   unwearable
  unrepaired
  unreportable
  unrepeatable
  unreformable
  unnerve
  unnerved