Ingratitude is a grave offense against God, and the closer to God we think we are, the more we are inclined to take divine grace for granted. Jesus makes this point in Luke 17:11-19. The psalmist continues to develop the theme by pointing out the possible problem with giving thanks. (see Psalm 106: 1-3)
The problem is this: humanity does not have sufficient words to praise God's goodness. So if we are not sincere in the expression of thanksgiving in our prayers to God, our voices may sound like a noisy gong or loud cymbal.