From some point in the 1980s, audio systems on the market began to compete for loudness. Of course, this was due to the demand from customers all over the world, eager to flaunt their loudness power and shake the windows of the whole neighborhood. Then, we began to talk about noise pollution: an excess of sound capable of altering the natural conditions of a particular environment. Unlike other forms of pollution, noise does not stay in one place or drift with the wind like a radioactive cloud. The point is that it is a well-known fact that excessive noise can affect the physical and mental health of humans and animals, among other things, not to mention that an excessive volume level can cause traffic accidents when using headphones.
For all these reasons, in addition to others, noise standards have been created for music, video games, television, movies, etc., and in each country, there is legislation to regulate this issue.
If you carefully analyze the volume level on music streaming platforms (such as Spotify or Apple Music) or audiovisual content (such as Amazon Prime or Netflix,) you will notice that everything sounds more or less the same, so you do not need to adjust the volume with the control every two minutes. This allows you, among other things, that if you’re listening to your favorite playlist in the car, and you go from a Beethoven sonata to a live Slayer song, you don’t have to adjust the volume drastically (well, that drastically). As the name implies, noise standards seek to drive standardization in sound. The problem is that these standards are not absolute, and every country handles things differently. If you are learning to mix and master, and, in the final part of the process, want to adjust your work to the correct noise standards (if you knew this was a mandatory step), you will probably be overwhelmed with the number of standards that exist.
Let’s start by considering a basic principle: every platform and audience has its sound standard. For a common broadcast platform, the requested code is EBU R 128. If it’s a rave on a private boat, of course, things will be different. The second principle you should keep in mind is that noise normalization is one thing and mixing and mastering processes are another matter. Very different issues. When you regulate the noise level, you are not manipulating the sound frequencies or minimizing production errors. Normalizing noise is just adapting to a particular standard, period.
The next thing you should know is one of the most common standards: Loudness Units Full Scale (LUFS). It’s used on major streaming platforms (like YouTube), not only because it oscillates at healthy noise levels for the human ear, but, by measuring the overall noise of the entire track, it allows for manageable standardization for massive levels of content. We are talking about millions of songs and videos, on a platform that today has more traffic than the entire Internet two decades ago. Here, you can find the Worldwide Loudness Delivery Standards.
It is impossible to determine that in the future a more homogeneous standardization will be achieved worldwide. The only thing you should know, for now, is that you should check the requirements for each production, for each platform, for each particular case. This is what all professionals do, like Enhanced Media to do things by the book.
The typical question of any mixing and mastering trainee is how loud the sound should be, and how to find the right balance between sound quality and noise level. The short answer is that it will always be best to stay within the limit. If the Deezer limit is -15 LUFS, the mastering should leave the sound below that level, never over the exact limit since they might automatically lower your quality by adjusting the sound to the standards. As loud as you can within the given limits, without spoiling all the mixing and mastering work before the ship sails.
Now, when it comes to television, the matter is a bit simpler. Although there are several standards, for different regions of the world, they are all in the -24 LUFS range, and this will keep you from breaking your head thinking about what is right for each occasion. In cinema, things have homogenized a bit, and, if you are familiar with broadcast standards, you will have no problems with movie sound. The norm is to handle noise at -27 LUFS, that’s all.
On the other hand, there are plugins that you can use and they will adjust the loudness for you. It is possible that automatization and AI may do the job in the future, however, and meanwhile, just pay attention to avoid wasting time.
The good news is that you don’t have to be an expert. All the information is already there, up to date, and you just have to be diligent and know what the noise requirements are for each specific case.