Loudness and Volume; Audio Broadcast Levels EBU R128

Research conducted by the BBC apparently reveals that around 60% of viewers admit to having some difficulty hearing television programmes. Sadly I don’t think there are comparative figures for previous decades but I can’t help wondering if there might just be some correlation between this and the growing tendency in TV production to save money by not using a Sound Recordist or employing the skills of a Dubbing Mixer.
On a related topic, many of you will have experienced the annoying

Loudness crop
Audio Metering with LUFS & PPM

jumps in volume between programmes and adverts as advertisers scramble to, literally, make themselves heard in a competitive market place. This has become a hot topic within the broadcast community in recent years, as regulators and broadcasters have striven to find a solution. A solution to what you may ask, just make the volume consistent so I don’t have to keep reaching for the remote every time there is an ad break! Well, I sympathise, but, preposterous as it may seem we have lacked an accurate way of measuring the loudness of these commercials.
Traditionally in broadcast, audio level, or volume has, most commonly, been measured as a peak value; that is to say the loudest point in the programme. Historically this was crucial in broadcasting because of the importance of not over modulated the transmitter. The drive to digital recording formats has also reinforced the dominance of the peak programme meter (PPM) as unlike analogue recording it has no toleration of peaks or overs, that is to say an input level which too high or too loud for it to cope with.
So, surprisingly, these commercials which have you franticly diving for the volume control don’t have a peak volume level which is any higher than the programmes they accompany, and yet they sound louder! Exactly why is beyond the remit of this short piece, (although I may return the subject in a future post), but suffice to say that is mainly achieved by tightly controlling the dynamics to make it the average level louder.
Alongside Peak Programme Meters we have also had V.U. or volume unit meters for many years (you may well have one on your home stereo) which show more of an averaged level than PPMs and so give a better sense of loudness but they miss certain critical factors of the audio signal, notably its peak level. So the industry found it had no way to accurately measure loudness and consequently no way of regulating the perceived volume of programmes and adverts.
Over the last few years a solution has been developed by the European Broadcasting Union which is a new type of metering as set out in their document: Loudness Recommendation EBU R128. This is quite different from the audio meters described above as they are both momentary measures of volume, that is to say it shows the signal level at any given split second in time. The EBU/ LUFS system factors in time, and actually measures the volume over a period, thus giving an accurate impression of the perceived volume to the human ear.
Some broadcasters across Europe have begun to implement the standard but take up is so far slow and whether it will become the universal standard it is designed to be remains to be seen. I certainly very much hope it does, as I feel that the viewing experience is marred by the current situation, and advertisers are actually alienating the viewing public; I wonder how many households are like ours and immediately mute the volume when to adverts come on. Of course that’s assuming they are not fast forwarding through them anyway, but that’s for another post!
Of course without dubbing mixers and sound recordists on productions you wonder whether there will be anyone capable of implementing the new standards, or indeed where the drive to do so will come from. All I would say is that it falls to all of us to demand good quality pictures and audio from the broadcasters we choose to view or subscribe to, and we should make our feelings known when they fall short. The alternative is to let yet another field that we once led the world in, slide into mediocrity!

If the new ‘loudness’ standards has been something you have been grappling with please don’t hesitate to contact us with your enquiries. We will be happy to supply further details of our R128 compliance service by return, just drop us a line via the contact page here!

Further reading:
Danny Cohen (Controller of BBC1 on the problem of audibility): http://www.bbc.co.uk/blogs/tv/2011/03/is-the-background-music-too-loud.shtml
BBC Acadamy guide on loudness:http://www.bbc.co.uk/guides/zs9jdxs#ztq6msg
EBU Guidance on R128 Loudness: https://tech.ebu.ch/docs/r/r128.pdf

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