Possible Clues:

• Vulgar laughter warmonger mostly echoed
• Vulgar laugh that's emitted by brass section from below
• Lord --, nickname applied to World War II traitor William Joyce
• Boisterous, loud laugh
• Derisive laugh
• Hearty laugh
• Wartime broadcaster making one laugh?
• Sound of a loud laugh
• Guffaw
• Hearty laughter