How to Fix Loud TV commercials - Part 2: Measurements

In part one of this series I gave an overview of the problem of loud TV commercials, or put more clearly, the inconsistent loudness of different items in a broadcast.

Before I dive into some solutions to the problem there are some audio concepts to understand. These relate to how audio is produced and measured. Inconsistent measurement and poor monitoring practices are at the core of the problem, so we need to understand these first.

There are two forms of measurement used when producing audio.

Level Meters

A level meter is a device for measuring variations in the electrical amplitude of the audio signal. The two most commonly used meters in broadcasting are the VU meter and the IEC standard PPM. Both measure audio differently, and experienced engineers know how to use them correctly. Measures of level are generally absolute and repeatable.

There are more sophisticated meters that purport to measure loudness as well; I will talk about these later.

Ears

The second and by far the most important tool, is the human auditory system. The ears combined with the brain is the most powerful psychoacoustic measuring device on the planet.

The human ear has two attributes that bear on this problem.

The first is that the perceived volume of a sound is based on the average loudness over time. According to Wikipedia:

The perception of loudness is related to both the sound pressure level and duration of a sound. The human auditory system integrates (averages) the effects of sound pressure level (SPL) over a 600–1,000 ms window.

The second important attribute is that it is optimised for processing speech. Human speech at 1 metre is typically around 60 dBA, measured with a sound pressure meter.

If you play a recording of speech and ask a group of people to set the volume so it is comfortable, the set volume tends to converge on 60 dBA. This applies when watching TV too.

Audio Processing

The two measures above would be fine except for two types of processing that are applied to audio to change the perception of loudness.

The first is equalization (EQ), which boosts or cuts selected frequencies. The aim in doing this is to improve the intelligibility and impact of the sound.

Mixing desks and digital editing systems have very complex controls that allow specific frequencies to be targeted for enhancement, allowing for fine-grained control.

The second first of these is audio compression or limiting. Put simply, this reduces the dynamic range of the audio so that the difference between the loudest and the quietest sounds are reduced. This allows the average volume to be increased.

Both of these are used in commercial production. The voice is EQed and compressed. Any music may also be compressed, and the finished product compressed again. It is common to see commercials with a dynamic range of less than 2dB.

In Practice

The audio of most TV productions has a dynamic range greater than 2dB. 15-25dB is more typical. This difference means that the level (on a meter) has to be set lower to avoid overload on the peaks. Commercials don't have any peaks, so can be set higher.

This is what happens in the average consumer's lounge:

They turn on the TV, and when the programme starts the volume control is adjusted so that the speech is at a comfortable volume. As stated above this will be close to 60 dBA. The dynamic range of the spoken material will be (say) 15 dB, and it must be set so that any peaks do not causes overloading in the broadcast equipment.

When a commercial is played it can be set 13 dB higher (2 dB dynamic) without causing electrical overload.

At the consumer's end, this means that content with a reduced dynamic range (like commercials) will sound a lot louder.

This is a massive simplification, but hopefully it makes sense. I suspect that I'll need to make companion video to this series to demonstrate things more clearly.

How to fix this?

Most discussion I've seen suggests that his is either a technical problem, or deliberate.

The technical crowd think that problems occurs because there are no agreed standards. There are standards, and though they are not always followed I think this is a side-issue because the problems of differences in loudness is operational in nature.

As stated in part one, I don't believe that most TV stations turn up the volume of the Ads. This is an error of omission. The problem persists because it is either ignored because it is not understood, or there is a belief that Ads must be louder in order to be effective.

Next time I will explain the solution to this problem by first presenting a simplified version, and then applying it to some real-world situations.

If you want clarification on anything here, use the comments section.

How to Fix Loud Commercials on TV - Part 1

This is the first of a series of non-tech posts about the volume of commercials on TV - why they are too loud and how to stop the problem.

The problem of commercials being too loud is the result of an arms race, of sorts, that has its roots in practices that were set decades ago. But it is not a race to the top, to world domination, to commercial success. It is a race to the bottom, to the lowest possible quality and the worst outcome for all.

The problem exists world-wide. The US have passed a law, and in New Zealand it is Labour Party Policy. Debates rage on forums, both public, amateur and professional about the cause of the problem and what can be done about it.

About Me

Before running Radio NZ's web operation I was a recording engineer. I started out as a Trainee Radio Studio Operator in 1981, and I've worked in commercial and public radio, on sports broadcasts, and music recording of all genres from early music through the classics, world music, jazz and rock. I've also recorded film scores, and mastered and re-mastered albums.

In the 80s I set-up the audio processing for a couple of Wellington radio stations, 91ZM (now ZMFM) and 2ZB (now NewstalkZB). I was in the fortunate position of having made commercials, done on-air sound mixing (called panel operating in some countries) and worked on the station sound (via audio processing). This allowed me to try out my ideas for improvement on-air, and hear the results first-hand.

Sometime in the mid 80's I was asked to contribute to discussions at TVNZ about the problem of loud commercials.

The Problem

I will start by defining the problem from the viewer's (and listener's) perspective.

You turn on the television to watch a programme. You sit down, adjust the volume so that it is comfortable for you, and start to enjoy the programme. As the show moves from scene to scene (assuming there is no ad break) the volume remains comfortable; you can hear everything that is being said, any  music and effects are neither too loud or too quiet.

Then a commercial break arrives. The volume suddenly increases. It is no longer comfortable to listen to - it is intrusive. During the programme you could have a side-conversation with your fellow viewers. That is now impossible. You reach for the remote and mute the audio.

This is the experience of hundreds of millions of television viewers.

The perception is that someone, somewhere, is turning up the commercials.

So, the problem in a nutshell: the volume of broadcast items is inconsistent, to the point of being disruptive and annoying.


Fixing the Problem

It is very unlikely that anyone, anywhere, is turning up the commercials. I've certainly never seen it.

The problem is caused by a number of technical and operational factors, and is (probably) rounded off by management being unwilling to deal with the issues for 'competitive reasons'.

The problem is complex, and I want to make the explanation accessible to people outside the audio industry. I'll spend a few posts looking at various aspects of the problem, explaining some of the basics of audio, hearing and listening before moving onto solutions.

Please leave any questions, or things you want explained in the comments.

Latest Radio NZ Browser stats

The latest browser stats for www.radionz.co.nz show some interesting changes when compared to previous years.

Browser	2011	2010	2009	2008
IE	41.2	50.6	56	63
Firefox	23.2	25.52	27.5	27.73
Safari	5.6	13.1	10	5.66
Chrome	13.8	8.75	4.2	1.47
Opera	0.7	0.9	1.02	1.08

IE is in decline, and IE6 is currently 3.6% of total browser share. Operating system use is also changing.

OS	2011	2010	2009	2008
Windows	72	81	84.8	89.3
Mac	15.6	14.2	12.6	8.5
Android	3.6	0.3	0.02	0
iPhone	2.5	1.4	0.56	0.19
iPad	2.4	0.63	0	0
Linux	1.53	1.4	1.45	1.72
iPod	0.5	0.35	0.22	0.08

Windows use is dropping, and mobile operating systems are on the rise. Mac use in 2005 was less than 5%.

The breakdown of mobile devices share in the last month:

Android - 38
iPhone - 27
iPad - 26
iPod - 5.33
Blackberry - 0.8
Symbian - 0.7
Sony - 0.19
Windows - 0.12
Nokia - 0.11
Windows Phone - 0.1

iPad users spend on average twice as long on the site.

Over on Geekzone Mauricio has posted page speed info for his website.

Here is similar information for Radio New Zealand.

Average web page load time distribution in New Zealand:

All regions:

Slowest cities:

This is running on a server based at ICONZ running Rails 3.1.x.

The key thing we've done to make our site fast is reducing over-the-wire times by bundling assets, using compression where we can, and setting far-future headers for static content to ensure it can be cached somewhere else. The markup is also as clean as we can make it to ensure fast rendering.

Radio NZ's embedded player

Last week Radio New Zealand released its new embedded player to the general public.

The graphics were designed by Clemenger BBDO in Wellington and implemented in Flash by PixelDepth in Auckland. The player (and server software) took 3.5 person-days to code, implement and test.

The player can be used by anyone (subject to terms of use) to embed Radio NZ audio content on their web pages.

While some people will be disappointed that the player does not work on iOS devices, the decision to make this first version in Flash was carefully considered. The core web team at RNZ is small - there are just three of us working on a range of projects. At the moment we are working on a complete redesign of the site, and on replacing our CMS, not to mention planning web coverage for the upcoming election.

A few years ago I started work on an HTML5 based player for our audio. The code is still available on Github. One of the impediments to completing this project was the lack of time to debug the application. At the time browser support for HTML5 was patchy. Building that player gave me a good idea of the level of engineering required for a complete package. I take accessibility very seriously. Any player has to work on all platforms, and for screen readers.

I have started planning for release 2 of the embedded player, but it will need thorough testing before release. We didn't have the time to do that now. I'm sure you all understand!

The new CMS is providing the data-backend for the new player, and audio content is delivered from our content delivery network. Both of these are completely platform agnostic. The iframe technique we are using will allow the player to be updated in the future, and for this to appear everywhere.

The player is already being used more widely than I'd expected. Other public broadcasters like NPR, special interest sites like Treetools, and Cycling Wellington, blogs, not to mention local news websites.