Possible Clues:

• The North listens to them, or gets close to it
• The North gets close to getting sound with them
• Gets warmer, perhaps
• Leaders of naval expeditions always raid southern approaches
• Is this approaching what goes on ahead of the North, perhaps?
• Gets close to making the North get sound
• Gets warm
• one gets close to getting the north sound
• Perhaps they get the sound of the north as it approaches
• Gets close to unquantified number of listeners