4 Bible Verses about Trumpets For Signalling

I was [rapt] in spirit on the Lord's day, and heard behind me a great voice as of a trumpet,

AFTER these things I beheld, and, lo! a door was opened in heaven, and a voice, the first which I heard, as of a trumpet, speaking to me, said, Come up hither, and I will shew thee what things will be after these.

Therefore when thou givest alms, sound not a trumpet before thee, as the hypocrites do, in the synagogues, and in the streets, that they may have glory from men. Verily I say unto you, They receive their reward.

and the sound of a trumpet, and the voice of words, which they who heard, earnestly begged that the discourse might not be directed to them: