Sunday, June 10, 2007

My Brain Hurts.

Earlier today I was channel surfing.

I landed on a particular channel and instantly started to feel irritated. Not in my usual way of stumbling across yet another crappy reality TV show, but something I couldn’t quite put my finger on. I was watching a show I liked, and despite the fact the volume wasn’t too low or high, I felt a headache coming on.

Not realizing at this point it had anything to do with the TV, I changed the channel, and I felt ok again. Changing back, I started to feel irritated again.

It’s tough to describe the actual feeling, but it was a sort of mild-claustrophobia. Imagine trying to work out a complex math problem with someone standing over your shoulder, reciting random numbers and you’ll know what I mean.

Then I started to realize that somehow the audio was making me feel claustrophobic. Even though I had the sound fairly quiet so Sunny could sleep…it somehow still felt too loud, but if I put it any lower, I’d be unable to hear it.

I’d noticed this on and off for a good few months, but this was the first time I suspected the TV of being the problem. Sometimes I’d be feeling just peachy, and within moments of turning on the TV, even if it was a show I’d been looking forward to, I’d start to feel irritable and ‘boxed in’.

Today the answer hit me. Audio compression.

This video explains what I’m talking about.

For the bandwidth impaired, or people who can’t be bothered watching the video, I’ll give you a quick rundown.

It’s become the ‘fashion’ recently to compress the hell out of audio tracks. This compression gives the audio track and much ‘thicker’ and fuller sound by increasing the overall loudness of the track.

For example, when I worked in a clothing store, we had a multi-CD player that piped music into the store. However, we couldn’t mix newer CDs with older ones for one reason; When the volume was set to have the newer CD’s playing at an appropriate level, the older ones were too quiet to hear. Why? The newer CDs were much more compressed and therefore much louder.

So what’s the big deal? If compressing makes the sound louder, you can just turn it down, right?

Well…no. The main side effect of over-compressing audio is that it ‘flattens’ the overall track. Basically, every instrument and vocal is played at the same loudness level.

This doesn’t sound like a huge deal, but it’s more important than you think.

The human ear isn’t really equipped to deal with this type of sound. With natural, non-recorded sounds, we’re used to hearing a large range of different volumes. For example, when listening to music, it’s likely the drum hits will be louder than the vocals, the lead guitar slightly louder than the rhythm guitar. When all of these sounds hit our ear at the same loudness level, it’s incredibly tiring.

Basically, imagine driving along and the sound of your engine, the music on the radio, the person next to you talking and even the sound of the other traffic and birds singing outside all reach you at exactly the same volume level. You automatically try and focus on a single sound, but this is made a lot more difficult because everything else is at the same level.

Focusing on a particular sound is something we do automatically with all sounds, and because we expect to hear certain things louder, our brains fool us into ‘hearing’ certain sounds more loudly. It’s the auditory version of an optical illusion. (For an example of this, get two or three people to talk to you at the same time. Whichever one you focus on you’ll be able to understand, and the other two will suddenly sound like unintelligible background noise).

You may think I’m talking complete do-do here, but a few minutes research on Google backed me up. The problem is that it’s one of those problems that’s hard to detect. At the back of your mind you know that something isn’t quite right, start to feel the symptoms, but don’t actually know why.

As one audio expert put it “It takes a while to notice over-compression, but once you notice it, it becomes incredibly difficult to un-notice it.”

If you think about it, you probably own a lot of music that you find tiring to listen to but don’t know why.

So, when watching TV shows with compressed audio, the dialogue, background noises, gunshots or whatever all reach your ear at the same volume. You don’t really notice it because if you’re watching ‘Star Trek’ you’re focusing on what Picard is saying and not on the background thrumming of the warp-engines.

Essentially, you’re trying to focus on one thing, and everything else is jumping up and down for your attention.

In the end, I checked my cablebox settings. It turns out that there’s an option to adjust the compression level of the audio…and mine (The factory default) was set to high. I turned compression off completely, and noticed the overall volume drop considerably.

So I adjusted my sound system to compensate and can honestly say I instantly felt better. I switched back to the channel that had started to give me a headache and found it sounded much better, and it also didn’t feel like I was trying to breathe through cotton-wool.

To close today, I’d be interested to hear your thoughts on this. Have you ever been watching TV and started to feel headachy or irritated? If your cable box allows you to adjust compression settings (it should be under the main menu under ‘audio options’), see what it’s set at and try setting the compression to ‘off’ and see if you notice a difference.

Long story short, the idea that longish periods of over-compressed audio is tiring isn’t a theory but proven fact. If you’re just listening to a single 3 minute track, it’s likely not to bother you, but a whole album or two-hour movie?

It’ll be interesting to see how many people this actually effects, and how many people have felt something is wrong, but not known what.

Let me know your thoughts!

4 comments:

MC Etcher said...

Very plausible. Apply for a grant and let's do a research study!

OzzyC said...

It makes sense, but I haven't experienced it. I think you should do a bit more research and follow up on the Geekology blog. You may want to include how you changed the compression settings on your cable box.

Kato said...

Interesting.

manda said...

I'm not sure if I've ever experienced this through the TV. On the radio, however, the DJ always has a deep voice, that the bass is boomin, and he sounds too loud, so I turn it down, and it's almost too quiet. Maybe that's a big reason why I don't like him hahaha. But then he sounds like a fruit when I turn the bass down..

And like MTV, their new live shows, like the Music Awards, I don't know why, but I reallly really really get irritated at the picture quality, and it's just awkward, so when the awards come around in like August, watch it and tell me what you think. I'm not sure what other shows do this, but I've seen it numerous times.