EZEKIEL 1:25
"And there was a voice from the firmament that was over their heads, when they stood, and had let down their wings." [AKJV]
A voice spoke from beyond the expanse over their heads while they were standing still with their wings folded. [Ezekiel 1:25 FBV]
Well let me add this Bible Translation [Good News Translation]:
[Ezekiel 1:25 GNT] — But there was still a sound coming from above the dome over their heads.
Meaning, after the Living Creatures shut down their Sirens by bringing down their Wings since they stopped moving, yet a Voice or Sound would still come from their "Heaven or Firmament" above their heads.
I tell you, in the heavens one may hear "Voices" from Firmament (from Heaven)(Revelation 14:13,2, 11:12, 10:8, 2Peter 1:18), from Walls, from Floor/Ground, from Altar/Stones (Revelation 9:13), from the Temple (Revelation 16:1), from Clouds, from Wind or Whirlwind, from basically things that are not Living Creatures but are Living Things. In this world, living things are living creatures; but in the realms of heaven Living Things are not Living Creatures, and all things are living things in the presence of God who is Life and makes all things alive.
Infact, the same Voice could be heard coming from two different locations at the same time, such as this Voice that was coming from the Temple and at the same time coming from the Throne:
[Revelation 16:17] — "And the seventh angel poured out his vial into the air; and there came a great voice out of the temple of heaven, from the throne, saying, It is done."
What you saw in this Bible verse above is that immediately the Living Creatures ended their own Sirens, the Firmament over them uttered a Voice, Speech or Sound as if the Firmament was saying "Amen" to the shout of "HalleluYah" the wings of the Living Creatures made.
Naturally, there are animals that are in the habit of responding or shouting back to their colleagues that had cried out load. Sometimes, when a hen is crying out loud, a matured cock would also cry out loud in responding to the hen's outloud. Even so, when the Heavens (beings) declare the glory of God loud enough, the Firmament (heaven) respond to them or join them to show signs of God's Handiwork. Now look at these three elements proceeding from the Throne of God in this Bible reference:
[Revelation 4:5] — "And out of the throne proceeded lightnings and thunderings and voices: and there were seven lamps of fire burning before the throne, which are the seven Spirits of God."
Notice that whenever lightning goes forth, thunder roars as backup. But it's not only after lightnings that thunders roar, because Thunders also roar after they hear Voice or Voices that are powerful enough to touch them. If you are on earth, and you cry out loud with a voice so powerful to touch the feeling of a Thunder in heaven, the Thunder will respond to you and thunder or roar back to you as sign of respect. Example as written:
[Revelation 10:2-3] — "And he had in his hand a little book open: and he set his right foot on the sea, and his left foot on the earth, And cried with a loud voice, as when a lion roars: and when he had cried, seven thunders uttered their voices."
These Living Creatures, Rabim, had their Wings so loud with powerful majestic Voice as the Voice of the Almighty God, Voice of Speech, the Voice of mighty Hosts, the Sound of great Waters. As soon as they finished sounding, the Firmament over them showed Its respect by responding with a Voice. This Voice was heard, coming from the Firmament over them, but no angel or living creature was credited as source of the Voice, just as this:
[Revelation 19:6] — "And I heard as it were the voice of a great multitude, and as the voice of many waters, and as the voice of mighty thunder, saying, Alleluia: for the Lord God omnipotent reigns."
Ezekiel began to hear Voice coming from heaven (Firmament) above the heads of the Heavenly Beings. John also witnessed three times Voice coming from heaven above the Head of Jesus Christ, before John saw and heard more in Revelations.
°1° The first time John witnessed a Voice coming from the Firmament or Heaven above the Head of Jesus Christ on earth:
[Luke 3:22] — "And the Holy Ghost descended in a bodily shape like a dove on Him, and a voice came from heaven, which said, You are My beloved Son; in You I am well pleased."
°2° The second time John witnessed a Voice coming from the Clouds of Heaven above the Head of Jesus Christ on earth:
[Mark 9:7] — "And there was a cloud that overshadowed them: and a voice came out of the cloud, saying, This is My beloved Son: hear Him."
°3° The third time John witnessed a Voice coming from the Firmament or Heaven above the Head of Jesus Christ on earth:
[John 12:28-29] — "Father, glorify your name. Then came there a voice from heaven, saying, I have both glorified it, and will glorify it again. The people therefore, that stood by, and heard it, said that it thundered: others said, An angel spoke to him."
Notice that the Lord Jesus Christ was not shouting outloud when the Voice from heaven came over Him. Ironically, when Jesus Christ was on the cross crying with a loud cry, no thunder or voice from heaven responded or regarded Him until He died, and then there was earthquake and agitations. The Voice that came when He was Baptized, Transfigured or Glorified, did not show-up when He was crucified and dying.