Thanks to current technology, we can listen to up to 128 sounds simultaneously. We explain how the Oscar-nominated films were recorded.
The Dolby technology was first used in 1971 in A Clockwork Orange, Stanley Kubrick. The objective was to reduce the ambient noise (noise reduction).
Although Kubrick’s work, based on the novel by Anthony Burgess, is recognized for the psychedelia and violence of the images, the sound was an essential part of achieving that overwhelming atmosphere that the director wanted.
The problem was that on many occasions, the silence because the recordings produce a distinctive and annoying whistle that prevented just that, that nothing was heard.
In this case, the key was to adjust the recording level so that the music was always high and later, in post-production, lower the volume. Thus the noise would be canceled.
Thus was born the Dolby B, which has been improved by the current Dolby Atmos. Sound is essential in a movie, and this year, eight of the nine “Best Picture” nominees used this system, and all the nominees for the “Mix and Sound Editing” award, too.
How does Dolby Atmos technology work?
Dolby Atmos is a surround or surround sound format. The most popular systems work with five speakers and a subwoofer.
But while speaker equipment (hardware) is essential, it is not a sufficient condition, the way of recording the sound is also necessary.
In most movies and series, everything is mixed across channels, from music to vocals to sound effects. Each channel is one of the speakers in the surround system.
In this way, if there is a dialogue between two characters, the sound is transmitted and mixed with the central channel. If a chase occurs and vehicle noise passes from one side of the screen to the other, they combine with the left and right speakers.
This is effective, but “something” is missing. It is this “something” that makes Dolby Atmos technology special, and it is achieved without using channels as in the previous system.
Sound directors seek to determine precisely where Atmos technology is in any room, and they want a sound to appear.
In this technology, most sounds are treated as “objects.” Thus, instead of assigning a sound to a channel (that is, to a speaker), Atmos allows sound engineers to determine a location for each music.
Thanks to this, you can go from the right or center speaker to the lower-left corner or center of the wall. And now comes the complex.
As Ricardo Vinas, Senior Sound Consultant at Dolby Laboratories, explains, “what we do is render a map in three dimensions and place the sounds in the X, Y and Z coordinates that the sound engineer asks us to do.
It is a complex process that requires particular algorithms so that the effect is the same regardless of the size of the room or the amount of audience “.
In the same way that cinematographers focus on the light of each shot, colors, and tones, sound directors pursue not the only intensity and quality but also location: they seek to determine exactly where in any room With Atmos technology, they want a sound to appear.
For example, the Dolby Theater, where the Academy Awards are held, has 215 speakers and 285 channels. The entire system is capable of producing up to 128 sounds simultaneously.
Of course, not all theaters have more than 200 speakers. In general, the minimum is 64 in Dolby Atmos, enough to provide the 128 different sounds, if necessary.
But it does not finish here, and The Atmos system allows engineers to “script” the sound, directing the speakers individually to the exact place where they want the music to come.
“In general, the minimum depends a lot on the size and shape of the room – adds Vinas -. For this, some algorithms define the best configuration.
A minimum could be around 30 for a cinema, but this depends a lot on the shape and the size of the room. And when it is at home (the second algorithm), the Dolby Atmos technology works differently. We use reflective surfaces to take advantage of the fact that you don’t always have speakers on the ceiling.
The soundbars also incorporate an algorithm that allows them to measure the size and height of the place to produce that effect that makes us hear surround sound in three dimensions, even from above.
“The third algorithm is the one that allows Dolby Atmos to work on helmets as well and is found on most mobiles and tablets. Thanks to them, it is possible to reproduce an experience similar to that of cinema, but on a more intimate or individual level.
In short, films become more realistic, more alive, and exciting, thanks to this technology that has changed the seventh art.