Has anyone ever heard God's voice?
No one has every heard the voice of God. Some have heard God's voice.
"Ye have neither heard his voice at any time, nor seen his shape."
"And the Lord spake unto you out of the midst of the fire: ye heard the voice of the words, but saw no similitude; only ye heard a voice."
"Out of heaven he made thee to hear his voice ... and thou heardest his words."