mute

adjective
  1. unable to speak or remaining silent
  2. producing no sound or very little sound
noun
  1. a person who cannot speak
  2. Usage: sometimes considered offensive; ‘person with speech disability’ preferred
  3. a device used to soften or muffle the sound of a musical instrument
verb
  1. to make something quieter or silent
  2. to turn off the sound on an electronic device

Examples