Codes and Conventions of Radio Trailers

• Music bed - no lyrics/instrumental versions, cannot overshadow v/o
• Sound effects anchor theme of doc
• Sound bites and/or extracts from documentary
• Intonation changes, i.e pitch and tone 
• 30-40 seconds long
• Beginning must be clear as to grab audience
• Should intrigue audience
• V/O same person as documentary and is intercut throughout trailer
• Hint at what's going to be on the documentary
• Schedule at the end, usually with a different voice
• Pose questions
• Same theme and slogan as print and from the same campaign