“The people therefore that stood by, and heard it, said, that it thundered: others said, An Angel spake to him.”
1611 King James Version (KJV)
12:29 The multitude who stood and heard - A sound, but not the distinct words - In the most glorious revelations there may remain something obscure, to exercise our faith. Said, It thundered - Thunder did frequently attend a voice from heaven. Perhaps it did so now.
Joh 12:29 An angel spake to him. All heard the sound of the divine voice, but it was not clear to all what it was.