Listeners to a BBC Radio 4 drama were given the chance to switch which character was narrating a story as part of an interactive experiment.
The characters are trapped in a flat
The Dark House was a horror/thriller featuring three characters - Lucy, Jim and Kelly - trapped in a flat.
During Tuesday's broadcast, listeners voted to change the perspective from which the drama unfolds, but the storyline remained the same.
The Dark House was broadcast at Tuesday at 2300 on Radio 4 and via the internet.
The story began from the point of view of Lucy, a young radio presenter, but as the story unfolded the character was changed to give a different perspective.
The points in which the perspective switched occured at different intervals, with text and phone votes counted every three minutes.
"Everyone thinks that interactive drama is about listeners changing the ending of the drama, but we're actually discovering it's much more than that," said Ashley Highfield, BBC director of new media and technology.
"The Dark House allows users to change their perception of the story by seeing the plot unfold through the eyes of three very different people. There is a much greater sense of participation."
Producers recorded 105 minutes of possible dialogue and action for the 45 minute drama, with 12 opportunities to switch the perspective.
Technological challenges included arranging all the characters' viewpoints, and accompanying music, so the listener is not distracted from the story once it has been switched.