Why are advertisements louder?

[Donald McGlinn]

Why do advertisements on TV sound louder and yet don't register as louder on a sound measuring device?

[CFTraveler]

WHAT DO YOU MEAN?

[DarkChylde]

once you educate yourself on subliminals and how advertising really works you can easily work out the angle and equation on every add in the first go that might consequently make the add stand out more as barren and devoid of message.

why is everything so blase these days ? *tee hee hee* couldnt resist

[sono2]

I used to work in broadcasting, & frequently had calls from people asking this very question. Ads/spots are recorded by different media houses, but should all be "equalised" when they are broadcast. However, it seems that this never happens in practise; I feel certain that the advertisers intentionally MAKE them louder, thus defeating their own purpose, as I, for one, equally "automatically" mute ads as they come on! It also seems to depend on the flighting schedule, they seem louder during peak hours!

[CFTraveler]

I second that one. I mute them and leave the room if possible. Since there's always something to clean, it's very possible.

[mick]

One trick that I have read of is to lift the lower elements giving an overall boost and more presence.

[Seeuzin]

Ooh a sound thread!

TL;DR version: It probably to do with the compression.

Long version: Let me give an example. MP3 format sound is a sound-compression format which removes all frequencies which are inaudible to human ears, as well as many frequencies which are audible but on the "fringe" of human hearing. .WAV, on the other hand, retains almost all frequencies that were present in the original recording of the sound.

You might not think it, but when paying attention, this actually has quite a noticeable effect. If you take a song that was originally recorded to .wav format, and convert it to an .mp3, many people will report that while the volume of the song is the same (and is discernable as such by looking at a volume meter,) the mp3 sounds less "rich." I can hear this difference when I convert .wavs of songs I like to MP3, and would describe it as the sound being less "in-your-face." The notes played are the same, but since the very lowest and highest frequencies are cut out, the sound sounds a lot less full. It's a hard quality to describe.

"Wait, how can you remove frequencies from a song without changing the pitch of the notes? Doesn't pitch depend on frequency?" Surprisingly, not entirely. If you want to see for yourself, download Buzz (www.jeskola.net) and play with the lowpass and highpass filters. Lowpass will filter out high frequencies and allow smoother-sounding parts of the sound to pass through, whereas a highpass filter only allows higher frequencies, producing a more grating kind of noise. This is part of why two bass synthesizers can play the same note, an A sharp, for example....yet one can sound smooth, and another can sound grating, gritty, and edgy. It's the exact same note, but with different filtering effects, different frequencies will come through more prominently, and this changes the quality of the sound (without changing the note played.) These kind of filtering effects are used often in dubstep to "mangle" the bass notes and get them to sound they way they do. (I may dislike Skrillex, but he's kind of a genius at filtering.)

So to my point...changing the frequencies present in a recording changes the way it sounds to the human ear, whether radically (aggressive filtering) or subtly (compression.) It's entirely possible the audio is less compressed in the advertisements by design. Lack of compression gives the sound a more "in-your-face" quality (which is what advertisers want)...without changing the volume on a measuring device! Sneaky. And I wouldn't have believed it had I not played with this stuff and heard it for myself. Hope this helps.

[CFTraveler]

I also read that some metal recordings are compressed in a way that makes them sound louder, and makes the quality less good. This made me a little angry, because I just kept thinking 'stereos today' are crappier than the ones from 'back in the day'.


Oh, and, gettoff my lawn!

[Seeuzin]

*nods* compression doesn't actually make the music louder, but it can make the volume able to be increased more without hurting your ears as much as cranking up the volume on the uncompressed version would. Subjectively, the volume on an uncompressed song at X volume and a compressed song at X + a few decibels volume can sound the same, even though the compressed version is being played louder. Like you'd said this is one way to make a metal song louder without making people's ears complain at them. :p

Long version: Let's say you have a song that you're playing at a certain volume. Throughout the song, there's a bass synthesizer that plays a sound that has a constant "volume spike" in the 300Hz-ish range. If you played this synthesizer's track solo and made a graph of its sound, you would see it as a relatively constant volume level in most frequencies, with a spike around 300. (At the bottom is my way oversimplified graph thingy version of it drawn in MS paint. :p)

So say that your comfort level for max volume is Y decibels. You want to listen to your music loud, so you turn up the volume to that level. But while most of the synthesizers in the song behave, there's the one bass synthesizer that has the volume spike. In the 1000hz, 2000hz, 3000z etc range it's fine, but in that one small range it's producing sound at Y + 5 decibels! The end result is that it's uncomfortable on the ears...so you have to turn the overall volume down to Y minus 5 decibels, so that that no portion of the frequencies in the song exceed the max volume your ears are comfortable with. (From a technical standpoint that's what's happening; subjectively it feels like "ow that kills my ears!" and you have to listen to the song at a lower volume.) (This is a made-up example, the numbers given are unrealistic but it's just to get the idea across.)

Compression can automatically "smooth out" the volume spikes in a song. If you master a song right, it tends to make it more pleasing to listen to, because there aren't any unruly spikes that grate on a listener's ears. If you REALLY compress a song as I suspect you're talking about with metal...there are very few spikes, which means you can get the volume closer to that maximum volume level of X decibels without discomfort. But as you'd said, the sound is a lot less rich.

[CFTraveler]

Thanks for the explanation. I see it now.