BBC R&D

What we're doing

Binaural sound technology allows the creation of immersive spatial audio experiences for headphone listeners. This can enhance programmes when listened to on headphones as well as create immersive interactive experiences including virtual reality.

We are developing tools for production and delivery of binaural sound, as well as evaluating industry technology. By studying the perceived sound quality of binaural systems and fundamentals of auditory perception, we are working to improve the state-of-the-art. We are also working on practical methods for delivering high-quality binaural sound to our audiences.

Why it matters

In the last few years there has been a large growth in the number of people listening to programmes over headphones. This is largely thanks to the arrival of powerful smart phones, fast mobile data networks and services such as the BBC iPlayer. Currently all audio we hear over headphones is in stereophonic format, the same content that we play over loudspeakers. But listening to stereo programmes over headphones gives a flat impression with sounds coming from inside the head.

Binaural techniques can be used to create a richer sense of space in programme sound, giving a more exciting and immersive listening experience. This can be applied to traditional programme content but also to new interactive content experiences including 360˚ VR video. 3D sound is now available in cinemas, this technology can bring that kind of experience to listeners' headphones.

Our goals

  • Develop a state-of-the-art binaural production workflow
  • Validate the quality of user experience of binaural broadcasting
  • Develop technology to deliver binaural sound to our audiences
  • Enable the BBC to create world-class binaural content
  • Open standards that enable binaural broadcasting

How it works

Binaural techniques simulate the hearing cues created by acoustic interaction between our bodies and the environment around us. Audio signals are filtered to introduce these cues and give the impression that a sound source is located outside of the head at a given location in space. Our hearing system appears to be sensitive to inaccurate cues, it is common for binaural filters to create an unconvincing spatial impression as well as poor sound quality. Every person has an individual pattern of hearing cues that are created by their unique body shape, also these cues change as a listener moves. Natural binaural reverberation is also important for convincing effect. Achieving high quality binaural sound currently requires careful measurement and specialist equipment. To adapt this for broadcasting requires new techniques based on a better understanding of human hearing.

Outcomes

We have now created many pieces of binaural content which have been made available to our audiences. For Hallowe'en 2015, Radio 4 held a special Fright Night featuring two new scary and immersive binaural audio dramas. We have also applied our techniques to virtual reality production to push the boundaries of what is achievable in virtual reality sound. Our original piece the Turning Forest was premiered at the 2016 Tribeca Film Festival in New York. We have also collaborated to produce several interactive digital pieces for BBC Taster including Unearthed, in collaboration with the Natural History Unity and Realise.

We are now helping more teams in the BBC to apply binaural sound in their work.

Besides producing content we investigate production techniques and tools for binaural and immersive audio, including evaluating the latest market developments. This ensure that the BBC is at the forefront in terms quality and creativity in this area. This includes research studies into signal processing fundamentals and perception of immersive audio, as well as working to establish international standards.

If you're interested in working with us then please get in touch.

BBC Click explains...

Recently BBC Click featured our work on the Turning Forest. This video gives a great explanation of that piece and the project in general:

This project is part of the Immersive and Interactive Content section

This project is part of the Audio Research work stream

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