The voice of the Almighty - Thunder.
The voice of speech - Rendered in Jeremiah 11:16 “a great tumult.” Some take it to describe the rushing of a storm.
Related Commentaries of Ezekiel 1:24
Ezekiel 1:24
24 And when they went, I heard the noise of their wings, like the noise of great waters, as the voice of the Almighty, the voice of speech, as the noise of an host: when they stood, they let down their wings.