you are His sheep and you know His voice.
sometimes i hear Him calling, like from far away, indistinctly, and i can't make out what He says -
He's saying then, "come nearer to me, seek me out"
like i'm a sheep down in the thicket, and He stands on the hill, calling me out of the brambles.
dig then into His word, get alone with Him and look for Him in prayer - ask Him to help you hear clearly, and He will!