Radio is an ephemeral medium. Each word and sound is gone as quickly as it arrives, and listeners can’t go back and reread something to remind themselves who’s who and what’s what. It’s also a medium from which people are easily distracted — they’re almost always doing something else while they’re listening. So make sure your writing is clear, vivid and engaging. Don’t get bogged down in unnecessary detail. Use shorthand and summarization, round numbers and comparative figures, whenever possible and appropriate. Keep your characters and voices clear and distinct. Pay close attention to transitions between scenes and themes, and make good use of signposts — where we’re going — and reminders — where we’ve been.
— Peter Thomson, environment editor for PRI’s The World