In this week, looking forward to the Baptism of the Lord, the gospel passage from Luke tells us that Jesus hears a voice from heaven saying to him, "You are my Son, the Beloved; with you I am well pleased. In the passage from Isaiah, the Lord speaks to Jacob reminding him that the Lord is the one who created him, who redeemed him, who will be with him.
The lectionary response is Psalm 29. It begins by reminding us of those qualities that the Lord possesses, the ones that we need to remember that the Lord possesses, and that we are to worship the Lord. The Lord that saves. The Lord that announced to Jesus, "You are my Son."
There shouldn't be any secret to this. The Lord's voice has spoken in a way that we should be able to recognize. Thunders. Powerful. Full of majesty.