"When the creatures moved, I heard the sound of their wings, like the roar of rushing waters, like the voice of the Almighty, like the tumult of an army. When they stood still, they lowered their wings." NIV translation
Ezekiel gives several examples of the noise that the creatures made with their wings. It reminds me of the heralds who used to travel before kings and blow the trumpet to announce the coming of the king. When they stop, they lower their wings just as the herald would lower the trumpet.
"Then there came a voice from above the expanse over their heads as they stood with lowered wings. Above the expanse over their heads was what looked like a throne of sapphire, and high above on the throne was a figure like that of a man." NIV translation
Above their heads is the throne of heaven and Jesus sitting there.
This is much like the experience that John had in Revelation and he gives us a description of Jesus there as well.
"I saw that from what appeared to be his waist up he looked like glowing metal, as if full of fire, and that from there down he looked like fire; and brilliant light surrounded him. Like the appearance of a rainbow in the clouds on a rainy day, so was the radiance around him." NIV translation
The descriptions of Christ are consistent throughout the Bible as He is a consuming fire and the source of light. The rainbow was given to mankind as a reminder of God's promise not to destroy the earth by flood (see Genesis 9). Likewise, this vision is a reminder of the promise that we will be in His presence for eternity.
"This was the appearance of the likeness of the glory of the Lord. When I saw it, I fell facedown, and I heard the voice of one speaking." NIV translation
Ezekiel did his best to describe the presence (glory) of God. His reaction was the same as everyone else throughout the Bible and that was that he fell on his face in worship. Then, he heard the voice of the Lord and we will see in the next chapter what God says to him.