'Sound of the Trumpet' in the Bible

My soul, my soul! I am in anguish! Oh, my heart!My heart is pounding in me;I cannot be silent,Because you have heard, O my soul,The sound of the trumpet,The alarm of war.

How long must I see the standardAnd hear the sound of the trumpet?

“And I set watchmen over you, saying,‘Listen to the sound of the trumpet!’But they said, ‘We will not listen.’