4 Bible Verses about Trumpets For Signalling

I was in the Spirit on the Lord's day; and I heard behind me a great voice as of a trumpet,

After these things I saw, and, behold, a door opened in Heaven; and the first voice which I heard was as a voice of a trumpet speaking with me, saying, "Come up hither, and I will show you the things which must take place after these."

When, therefore, you are doing alms, do not sound a trumpet before you, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say to you, they receive their reward.

and the sound of a trumpet, and the voice of words; which voice those who heard entreated that no word more should be added to them;