Since the earliest days for radio drama, some of the sound effects used in live
programs were recorded. It just wasn't possible to say fly an air plane in the studio
and the director wanted a sound more realistic. Recorded sound effects also allows
you to create a specific effect, but have control over it's creation, edit it,
modify it or combine it with others.
Finding a quiet space to record can be a problem. Mike McDonough tells the story or venturing into the desert of Utah to record gun ricochetes. Once set up and ready, he had to stop while an Army convoy approached and passed. I have spent hours in the wet lands of Jekyll Island trying to record morning nature in between jets passing over on their way to Florida.
More to come.