As of 1 January 2012 all members of the European Broadcsting Union (EBU) will change their audio specification from peak normalisation to loudness normalisation. This will apply not only to broadcasters but also to the entire audio production and post-production fraternity.
The new EBU specification means that audio measurement for the creation and broadcast of audio content as we know it will change.
It has long been a problem that some broadcast audio is perceived louder and that loudness fluctuates considerably depending on the type of processing applied to the audio. For example, commercials always sound louder because of audio compression. This has a tendency to irritate the listener. On peak programme meters (PPMs) the level looks fine and within specification but the ear tells a different story.
“Loudness normalisation aims to correct this,’ says Danny Booysen of Creative Broadcast Solutions (Pty) Ltd. “New metering components are therefore required to facilitate engineers to produce content that adheres to this specification. Creative Broadcast Solutions in South Africa represents Merging Technologies, which carries Pyramix DAWS and there are already metering software plug-ins available for Pyramix.’
Inala’s Colin Wainer continues: “The EBU has issued a technical recommendation document, EBU R128, which provides the practical guidelines to audio loudness implementation. This document describes in practical detail the most fundamental changes in the history of audio in broadcasting. An example of this is the change of the levelling paradigm from peak normalisation to loudness normalisation. Details of the EBU R128 document can be found on the EBU website – http://tech.ebu.ch/.’
The broadcast world is changing to file-based workflows. As such, the basic principle is that loudness normalisation and dynamic control of the audio signal is recommended, especially for new content.
Metadata is an integral part of file-based systems; it can be active metadata (potentially changing the audio signal) or descriptive metadata (providing information about the signal). The three main parameters are programme loudness, loudness range and maximum true peak level. These form the core of loudness metadata in audio files.
“Dolby as a proponent of metadata and the control of loudness normalisation has equipment that enables a broadcaster to implement in the traditional audio or in the file-based workflow,’ notes Wainer. “Inala Broadcast together with Dolby have expertise in loudness normalisation and we offer our assistance to any interested party wishing to understand and implement loudness normalisation in their facility.’
Louis Enslin of Produce Sound has been using software loudness metering for a while. “But this has just been for my own purposes, as we still need to adhere to the delivery requirements that we have at the moment, which are based on peak normalisation. Consequently, we have to use our PPM meters to set levels for programmes and commercials.
“I really hope that the same change will filter through to South Africa, but I don’t expect it to change as soon as 1 January 2012. The reality is we are a bit behind international trends, especially when it comes to technological changes like these. So there will probably be a bit of a delay before we are required to deliver material using the loudness normalisation specification.
“This new ruling will help to bring an end to some of the loudness wars out there, and assist in achieving a good sounding mix on air, instead of an over-compressed, thin sounding, tinny mix. As far as gear goes, there are a couple of software plug-ins out there that are specifically made for this, and also a couple of more expensive hardware units. For those engineers who don’t have one, you’ll have to get one’
It’s an awesome step forward and will finally end the different audio levels often experienced during a broadcast, particularly related to the compressed soundtrack of commercials.
