Revelation 10:3

he cried out in a loud voice which resembled the roar of a lion. And when he had cried out, each of the seven peals of thunder uttered its own message.

Revelation 4:5

Out from the throne there came flashes of lightning, and voices, and peals of thunder, while in front of the throne seven blazing lamps were burning, which are the seven Spirits of God.

Revelation 8:5

So the angel took the censer and filled it with fire from the altar and flung it to the earth; and there followed peals of thunder, and voices, and flashes of lightning, and an earthquake.

Revelation 14:2

And I heard music from Heaven which resembled the sound of many waters and the roar of loud thunder; and the music which I heard was like that of harpists playing upon their harps.

Revelation 15:1

Then I saw another marvel in Heaven, great and wonderful--there were seven angels bringing seven plagues. These are the last plagues, because in them God's anger has found full expression.

Revelation 15:7

And one of the four living creatures gave the seven angels seven bowls of gold, full of the anger of God who lives until the Ages of the Ages.

Treasury of Scripture Knowledge

Summary

And cried with a loud voice, as when a lion roareth: and when he had cried, seven thunders uttered their voices.

Bible References

Seven

Revelation 8:5
So the angel took the censer and filled it with fire from the altar and flung it to the earth; and there followed peals of thunder, and voices, and flashes of lightning, and an earthquake.
Revelation 14:2
And I heard music from Heaven which resembled the sound of many waters and the roar of loud thunder; and the music which I heard was like that of harpists playing upon their harps.
Revelation 15:1
Then I saw another marvel in Heaven, great and wonderful--there were seven angels bringing seven plagues. These are the last plagues, because in them God's anger has found full expression.