I watched this movie sometime during 2003-2006 about a radio station that broadcasts a story, much like how Orson Wells broadcast War of the Worlds.
Anyway, it was an East Asian-language film, as I was reading the subtitles. I swear it was in Japanese, but it could be Chinese or Korean. I don't know. I know they were East Asian.
The story at some point had a damn blow up. To make practical sound effects, the people used Styrofoam cups and paper to create the sounds. They did this throughout the story for most if not all the sound effects.
Another point of interest was that someone in charge appointed a different person to narrate the story, as he had a better sounding voice. The narrator was male.
That's all I can remember about this movie. I posted this same question years ago on Yahoo Answers, but nothing popped up.
EDIT:
Was almost certainly a Japanese movie. If I remember, there was a trucker or something that was totally captivated by this story over the radio.
I think the regular cast if you will, was not available for the show. As such, I think the story was heavily improvised, as the story changes quite drastically.
I think the effects were also locked up or something, as they used the flushing sound of a toilet as a damn bursting. The movie was made late 90's to early 00's, but not later than 2002, as the movie was on a channel that showed older movies, not recent DVD releases.