The enhanced binaural audio episode, which premiered on BBC One on Saturday, was screened to a group of students in Wales earlier in the week.
By wearing headphones viewers can create a 3D surround soundscape that places them at the heart of the action. New software developed by BBC Research & Development artificially mimics the subtle effect the shape of the viewer’s head and ears have on what they hear. This lets sound engineers give the impression of specific sounds like the creaks and groans of the old house in Knock Knock being in front, behind, or all around viewers.
Catherine Robinson, audio supervisor at BBC Wales, said: “The software BBC R&D have created enables us to completely immerse viewers in this extremely atmospheric episode. People will be able to hear the surround sound mix the way our engineers hear it in the studio, without the need for acres of cables, speakers and stands in their lounge. And as they can watch with a normal pair of headphones, they can experience the 3D audio wherever they want to watch this episode, whether on the bus, or on the loo, or in the garden.”
Knock Knock is now available on the BBC iPlayer.