'Trumpet' in the Bible

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

After this I looked, and, behold, a door was opened in heaven: and the first voice which I heard was as it were of a trumpet talking with me; which said, Come up hither, and I will shew thee things which must be hereafter.

And I beheld, and heard an angel flying through the midst of heaven, saying with a loud voice, Woe, woe, woe, to the inhabiters of the earth by reason of the other voices of the trumpet of the three angels, which are yet to sound!

Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates.