What does the sound of wings symbolize? (Revelation 9:9)

And they had breastplates, as it were breastplates of iron; and the sound of their wings was as the sound of chariots of many horses running to battle.

Revelation 9:9 - King James

⚪ The old-time Methodist hell-fire revival
⚫ The rest of the Lord makes a joyful noise to the glory of the Lord
⚫ The symbolic locusts let God’s judgment message be heard

⚪ The old-time Methodist hell-fire revival

Rev. 9:9 [...]
And the sound of their wings. — When engaged in "getting the power".—Rev. 9:3.
Was as the Bound of chariots. — The noisiest vehicles known in the Revelator's day.
Of many horses funning to battle. — The old-time Methodist hell-fire revival was in days gone by the noisiest place on earth, excepting the camp-meeting. Those good old days have long since gone.

Source : 🇺🇸 1917 - Studies in the Scriptures, Vol 7, The finished mystery, page 159 + Cover

⚫ The rest of the Lord makes a joyful noise to the glory of the Lord

Rev. 9 [...]
"And the sound of their wings was as the sound of chariots of many horses running to battle." (Vs. 9) When the Lord's remnant are in action they make a sounding noise which frightens the enemy. Their chief business is to make a joyful noise to the glory of the Lord. This is another proof that they are of God's organization. By the use of the radio and the millions of books they make a great noise; so it is thought by those who are frightened. One real Christian can put to flight a thousand ecclesiastical frauds. "One thousand shall flee at the rebuke of one." (Isa. 30:17) "Like the noise of chariots on the tops of mountains shall they leap, like the noise of a flame [...]

Source : 🇺🇸 1930 - Light, Vol 1, page 148 + Cover

⚫ The symbolic locusts let God’s judgment message be heard

Like a huge swarm of winged locusts that are capable of flying for a thousand miles or more, they unitedly make a noise that sounds like a squadron of war chariots rattling along to the beat of many horses’ hoofs into the battle. It is a terrific sound. The symbolic locusts shout as from the housetops and let God’s judgment message be heard over a vast distance in the territory that they cover. Fear of the enemy does not soften down their message to a mere whisper. Jehovah’s war declaration must be sounded loudly. He is responsible for the hurting of feelings that the message causes to the ones who are stung by it.

Source : 🇺🇸 December 1, 1961, page 719 + Cover