Out of heaven he let you hear his voice, that he might discipline you. And on earth he let you see his great fire, and you heard his words out of the midst of the fire.
Deuteronomy 4:36

If we hear or see God, it is only because He has caused us to hear and see Him. If we honestly seek, not demanding he conform to our expectations, he will reveal himself.

(Speaking of hearing God's voice from heaven... I just finished a video about Peter and the keys to the Kingdom and will be uploading it shortly.)