Possible Clues:

• Catch where GIs were once on the radio?
• Hover about the organ pick up
• Pick up broadcasts in this area
• Pick up by the ears?
• Catch a number of balls before he gets a run
• Hover shiftily. Are out to find what's being said
• Listen without the speaker's knowledge, maybe by accident
• Listen unintentionally
• Hover about and are prepared to eavesdrop
• Listen accidentally unknown to speaker