Series: Spring cleaning for your ears – We'll polish your audio knowledge! Episode 1

Episode 1: Why is it often difficult to understand the sound in films on television?

It can be the most exciting blockbuster, the most impressive cinema images... - but the sound?! How often do you find yourself looking forward to a relaxing evening in front of the TV, but it turns into a constant pressing of the volume control on the remote control: If you want to relax and listen at a comfortable volume, you constantly have to turn up the dialogue, which then means that the action scenes are too loud, and you then have to turn them down manually if you don't want to annoy those around you with too loud sound.

Why is this the case and why does it seem to have not improved for years, but rather gotten worse? There are various reasons for this. We will describe a few of them to you:

The type of sound recording directly on set

Elaborate blockbusters work with opulent images in which there is a lot of movement. The sound crew has a hard time positioning their equipment so that the sound quality is perfect. The image is in the foreground and microphones, for example, cannot be attached directly to the actors because then you would see them. So there is usually a distance between the recording device and the actors, which also means that unwanted noises are recorded that are difficult to remove from the soundtrack. Despite the wide range of post-production options, it can happen that speech intelligibility is not perfect even during production.

The difficult decision for or against music and effects

Today's films usually contain a lot more music and effects than films from the 1970s or 80s, for example. This is because it was technically more complex and expensive to produce sound for films back then. So the focus was more on making dialogue understandable in order to be able to tell the story, while music and effects were used more sparingly. Thanks to today's digital production options, there are practically no limits to the number of audio tracks available. These can be used much more time- and cost-effectively. This has led to more and more music and effects being included in films to accompany the dialogue, although there is always a risk that they make the dialogue more incomprehensible by overlaying too much sound information.

Films are produced for the cinema, not for the living room

Movies are usually mixed directly in a cinema hall so that they have a perfect effect. Let's imagine going from a cinema hall straight into our living room. What is immediately noticeable is that everything is different, nothing is comparable. In a cinema hall, the sound is reproduced via a large number of large speakers at cinema volume, i.e. loudly. This standardized volume is much louder than room volume and is even exceeded during the mixing phase because it feels great.

Craig Mann, successful sound mixer and Oscar winner for his mixes in films such as Kill Bill 2, Collateral and The Bourne Ultimatum, once described it in an interview: "In theory, it should be the same level that is displayed in the cinemas on the Dolby Cinema processors, so that you get more or less an exact translation of what you did in the mixing console. But what happened is that mixers and perhaps directors wanted the films mixed at a level that was simply deafening."

Much smaller speakers are used in the living room. Soundbars, for example, have very small speakers that cannot be compared to cinema speakers. The following problems arise:

• People hear differently at different volume levels. The film is therefore perceived differently in the living room due to its lower volume than in the cinema, for which it was actually mixed, and this affects the intelligibility of the dialogue.
• In order for the film to really pop, the rest of the film has to be mixed more quietly. Otherwise the loud parts would be overdriven. Therefore, the dialogues are generally mixed more quietly so that the music and noise in the louder parts achieve the desired dramatic effects.
• However, this professionally calculated volume gradation for cinema does not always work in the living room at home, as the much smaller and less powerful speakers have a different sound behavior.
• In order to be able to stream the sound cost-effectively, its quality is reduced. This is called compression. One advantage of this is that the soundtrack is less data-intensive and therefore requires less bandwidth. Another advantage is that the film runs more smoothly, even if you don't have a high-quality internet connection at home. However, this also means that the quality of the dialogue can suffer.
• No filmmaker can fully understand or prepare for the variety of devices available to get films into people’s living rooms.

Some filmmakers are therefore starting to create another film mix specifically for streaming, and another for stereo playback. But this then causes higher costs and is a logistical challenge as to which mix ends up in which distribution channels.

Statistically speaking, the vast majority of Germans still listen to their films via soundbars or other (stereo) speakers, and fewer have AV receivers for surround sound or Dolby Atmos. For most TV viewers, the multi-channel sound comes from two speakers in stereo. This is where the HDSX TV Sound Optimizer comes in: It translates the sound produced for the cinema into the sound environment of the living room at home. To do this, it optimizes the sound in PCM stereo, which means in uncompressed audio quality.

This means that no sound quality is lost, as it optimizes every detail with the highest processing quality. On this basis, it checks the incoming signal in real time and uses its HDSX.volume technology to increase the volume where the film's audio is too quiet for enjoyment in the living room, but leaves loud parts as loud as they are. It does not smooth out the sound, but retains dramaturgically important sound impulses. HDSX.speech also makes the dialogues stand out more clearly and in more detail from the background music and effects.

So you can sit back and relax, enjoy the movie blockbuster and put the remote control aside to adjust the volume.

Further information can be found in our video: