4 Bible Verses about Trumpets For Signalling

I was in the Spirit on the Lord's Day, and I heard behind me a loud voice like a trumpet,

After this I looked, and behold, a door standing open in heaven. And the voice, which I had first heard speaking to me like a trumpet said, "Come up here, and I will show you what must take place after this."

"Thus, when you give alms, do not sound a trumpet before you, as the hypocrites do in the synagogues and in the streets, that they may be praised by men. Truly, I say to you, they have received their reward.

and the blast of a trumpet, and the sound of a voice whose words made the hearers beg that no further word be spoken to them.