Possible Clues:

• Accidentally perceive with the ear
• Eavesdrop
• Accidentally catch something, perhaps
• Eavesdrop on
• Catch report of GIs in Britain during the war, as the saying goes
• Accidentally listen to
• Catch what was said of Americans in Britain
• Listen accidentally without speaker's knowledge
• Pick up report of GIs' wartime location
• Manage to catch some cricket and try