Usually God speaks to the people through a prophet or an angel (messenger).
But throughout the Book of Judges, the major theme is that the Israelites abandon faith in God, turn to idolatry, experience hardship and oppression due to abandoning their faith in God, and afterwards, they "cry out to the Lord" after recognizing their wrongdoing in turning to idolatry.
For example, Judges 10:10-10:11 says, "Then the Israelites cried out to the Lord, 'We stand guilty before you, for we have forsaken our God and served the Baalim.' But the Lord said to the Israelites..."
How does God talk to the whole community if a prophet is not mentioned as an intermediary between the people and God?