Spatial Audio Recording: The Predominant Trend in the Filming Future

Spatial audio, or three-dimensional sound, has applications in fields such as cinema, video games, virtual reality, or live music. We are talking about a new format that will revolutionize the way we listen to music or enjoy live concerts, movies at the cinema, as well as other forms of entertainment. Thanks to technological advances, the sound of the future will be in three dimensions.

When sound first began to be recorded, there was only one channel and the audio sounded homogeneous and in a single block: this is what is known as the mono system. Later came the stereo revolution which allowed recording and playback in two channels. The next step in the history of sound came with surround, an audio format with additional channels and speakers surrounding the listener, even creating a 360-degree sound sensation in the horizontal plane. Spatial audio, however, offers a sense of surround sound in all three dimensions, maybe closer to reality than reality itself. Spatial audio, also known as holophony or binaural audio, represents a new level: a sensation that the sound flows out from various points around us as if we were inside a sphere full of loudspeakers everywhere.

To record this type of sound you will require special equipment, of course. One of the ways it is produced is thanks to a system of twenty-five speakers and three subwoofers, plus advanced technology that has focused on this area of sound production. A series of specialized plugins, such as dearVR PRO, Harpex, or Dolby Atmos, among others. However, it is also possible to do it another way, and the key is always to have a series of high-quality loudspeakers at hand to locate a sound source with sufficient precision. In this way, a soundstage is created, and three-dimensional sound flows through the headphones, thus allowing the sound source to be located behind and above the listener. We are no longer talking about a stereo system, reproducing sound on the X-axis from left to right. Here, the Y and Z axes are involved as well. Spatial audio makes it possible to generate sound that seems to come from multiple directions by hacking the human brain somehow.

The mechanics behind all this is simple, really. The explanation is based on the distance between our ears, which is why surround sound is mainly heard through headphones. Having to use it through headphones has been one of the main reasons why its use has not spread faster. In music, it is usually sought that the sound is heard as close as possible through any device but in the case of this technology, if it is not heard thanks to a headset, the music would be heard differently. This is because spatial audio modifies different parameters such as frequencies or time lag. When it comes to headphones, the position can be adjusted well, but through the speakers, it is a little bit more complex than that.

To create the spatial audio effect, the brain is tricked into positioning certain frequencies in space. That is, the audio file is modified by copying the frequency spectrum, as well as other parameters, that our ears would hear if we were surrounded by the sound sources, such as instruments. With spatial audio, the brain interprets that the sound sources are in different places, though in reality what happens is that the sound is modified to apply specific parameters to make you think that this is the case. This makes it possible to create a spherical and totally immersive experience, with a result that not even a state-of-the-art system can achieve.

The starting point, then, is to modify the original audio, which will be recorded using microphones of different types, to reproduce the same frequencies and parameters that we would hear if we were surrounded by instruments.

Two years ago, Sony launched the 360 Reality Studio, which has a system of up to twenty-four object-based channels. The recording can differentiate multiple sources placed at different angles and combine them to provide surround sound. In addition, because it is object-based rather than fixed position, the sound can move dynamically.

The advantage of this system is that the most complex part is located in the recording studio. The end-user has to do almost nothing, just have an audio file in this format and set up their listening profile to get the right experience.

Of course, it is important to note that this format is not proprietary to Sony. Sony has simply pushed a new audio format, nothing more and nothing less; and the standard used by this tool is MPEG-H 3D Audio, an open format that supports almost one hundred and thirty channels, with sixty-four active speakers.

Every day, more tools will appear, and more brands will compete in this market. It is essential to keep in mind that this trend is growing, and has started a major breakthrough in the film industry. It forces experts, like Enhanced Media, to adjust to these new changes and face new challenges to reach new goals.

*The images used on this post are taken from Pexels.com