Friday, December 30, 2011

My take on out-of-office replies

About 5 years ago, when I got back from holiday, I had 1500 emails in my inbox. I had checked (but not answered) my email all through my break and I had worried about the growing backlog instead of enjoying the rest.

I did two things to fix this problem. The first was to start using operational accounts instead of personal accounts for work directly related to the website. The entire web team have access to these accounts, meaning if someone is away nothing gets missed.

The second thing was to set up an out-of-office reply. The point of this is NOT to tell people when I am back. The point is to provide the email addresses that they should be using instead, and saying who is on-call.

The other thing that I added was a note to say that I was not going to read ANY of the email received while on holiday - so if it was important, please resend the email when I got back.

This message caused a bit of controversy, but the effect was dramatic. While on holiday I knew I could completely forget about my email because those sending the mail would do the work for me! They would decide who to contact instead (from info in the reply), or to resend it later.

That first year I took a hard-line - emails were trashed automatically when received. Over 1,000 were in the trash when I got back. Only one 'important' email was resent. The second year it was about 200.

Now things have settled down I don't trash emails anymore, but I still have an auto-response stating who to contact for operational issues. And holidays are so much more relaxing.

Saturday, December 3, 2011

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.


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.