Following the development of a new standardised way of measuring loudness, there is a global move away from peak metering towards loudness metering.
Project from - present
What we're doing
We were involved in the assessments of new meters more than 10 years ago and have continued to play a major role in the further technical enhancement of the ITU standard meter. BBC R&D was one of the founding members of the EBU PLOUD group and has contributed significantly to the development of the EBU's revolutionary Recommendation R128 for loudness measurement and control, and its accompanying guidelines. We work with other organisations too, such as the AES and CENELEC, to ensure that standardisation efforts continue to improve the experience of our audience.
Why it matters
Unwanted loudness variations have been the source of audience complaints for many years. Although a large proportion of these complaints are about overly compressed advertisements on commercial television stations, the BBC still has opportunities to improve its own output. The development of better measurement techniques, and better production and distribution practices is clearly to the benefit of all our audiences. Close cooperation with other broadcasters and industry around the world to achieve a single, standard, measurement technique, reduces equipment and training costs, and speeds the development and adoption of improved working practices. Furthermore, BBC R&D has a responsibility not only to the BBC, but also to other UK broadcasters to ensure that they are not disadvantaged by international agreements.
- To have a better way of measuring loudness than the traditional quasi-peak meter
- To have a consistent way of measuring and controlling loudness shared by all the broadcasters
- To develop improved ways of working that are effective and efficient in delivering an improved quality of audio experience to our audiences
How it works
In about the year 2000, the International Telecommunication Union started a project to try to find a better way of measuring programme loudness. BBC R&D became involved in the assessment of newly-proposed metering techniques. Several years later, when a new international standard method, ITU-R Recommendation BS.1770, had been agreed, BBC R&D continued its involvement in standardisation, in collaboration with other EBU broadcasters in the EBU PLOUD group. It was in this EBU group that a 'gating' function, to prevent background sounds in loudness measurements producing misleading low results, was developed and tested, and submitted to the ITU-R to improve the basic meter. Along with that work there was also the drafting of a new EBU recommendation for the use of this new meter to improve the audience experience.
The scope of the whole project starts at audio acquisition in the studio and only ends at the final output of the receiver in the home. There have been many complex technical problems to be solved, followed by the production of explanatory documents to share with others the results of the consideration and experimentation that has taken place.
The EBU involvement ensures that the opinions and skills of representatives of many broadcasters can be used to produce the best possible outcome for all. The further standardisation in the ITU-R ensures that we have have a world-wide standard for the future, now ready to measure loudness of 3-dimensional channel-based audio.
Participation in CENELEC helps support the continuing development of regulations to prevent noise-induced hearing loss from the use of portable media players and thereby improve the quality of our audience's experience.
The ITU-R has produced a new Recommendation for loudness measurement, ITU-R BS.1770, and a related recommendation for meters, BS.1771.
The EBU has produced Recommendation R128 and the supporting documents Tech. Docs. 3341, 3342, 3343, and 3344, relating to meter design, loudness range, production and distribution, respectively.
The Technical Council of the Audio Engineering Society has published a Recommendation for loudness of audio streaming and network file playback.
Numerous broadcasters in Europe have already formally adopted R128, and several part of the BBC have now started to use it, although because of the size and complexity of the corporation, it takes time to complete a change such as this.
This project is part of the Audio Research work stream