muffled russian

• глухо́й

  deaf

  muffled, flat, toneless, dull, indistinct

  unvoiced, voiceless

  out-of-the-way, remote, god-forsaken

  dense

  blank

• глу́хо

  deafly

  dully, vaguely, in a muffled way (sound)

  out-of-the-way, remotely (place)

• глухова́тый

  somewhat deaf, hard of hearing, muffled