The voice of the Lord can be comforting or condemning, loud or soft. [Psalm 29]

However, here in The Revelation, we see voices in the plural. They seem to represent God’s majestic presence.

From the throne issue flashes of lightning, and voices and peals of thunder, and before the throne burn seven torches of fire, which are the seven spirits of God; Rev. 4:5

Then the angel took the censer and filled it with fire from the altar and threw it on the earth; and there were peals of thunder, voices, flashes of lightning, and an earthquake. Rev. 8:5

Then the seventh angel blew his trumpet, and there were loud voices in heaven, saying, “The kingdom of the world has become the kingdom of our Lord and of his Christ, and he shall reign for ever and ever.” Rev. 11:15 

Then God’s temple in heaven was opened, and the ark of his covenant was seen within his temple; and there were flashes of lightning, voices, peals of thunder, an earthquake, and heavy hail. Rev. 11:19