Spatial Audio definition (vs. spatial sound and 3D sound)

As someone who has dedicated his career to understanding and developing audio experiences, I recently had the opportunity to dive deep into the topic of spatial audio with Thomas Riedel.

Especially in the context of the new Apple Vision Pro, his podcast is no longer called Metaverse Podcast, but Spatial Realities.

Spatial audio describes how this technology enhances sound playback, allowing listeners to perceive sound from multiple directions, including above and below, creating an immersive and realistic audio environment.

More up-to-date than ever with Apple’s VR glasses

In our discussion, one example, we explored the fascination with all things audio and the increasing importance and sound field of 3D audio, which is no longer limited to Apple devices, but is also being adopted by other manufacturers and in various media such as films and the music industry.

Apple Music supports spatial audio and Dolby Atmos technology, featuring a rich catalog of Dolby Atmos songs for an immersive experience through compatible devices and headphones.

3D audio is slowly becoming mainstream. […] There was quite a lot of coverage, even in the Süddeutsche newspaper, where I was quoted in this article.

Podcast with an immersive experience that is not dolby atmos

Listen to the whole episode here. The article is based on a 10-minute discussion about the difference between immersive audio, spatial audio work and sound, traditional surround sound here, and sound waves etc.

High sound quality is crucial in crafting an immersive spatial audio experience, as it allows our brain to use spatial hearing to process sound waves from various directions.

I hope there is now a better 3D audio definition Spatial Realities Episode 43.

What is Spatial Audio?

Spatial audio is a cutting-edge technology that revolutionizes the way we experience sound. Unlike traditional audio formats, spatial audio allows listeners to perceive sound from all directions, creating a more immersive and realistic auditory experience.

Imagine being able to hear a bird chirping above you, footsteps approaching from behind, or a car passing by on your left—all with stunning clarity. This technology is not confined to a specific speaker setup; you can experience spatial audio through various devices, including headphones, earbuds, and speakers.

Whether you’re watching a movie, playing a game, or listening to music, spatial audio transforms the auditory experience, making it feel as if you’re right in the middle of the action.

How Spatial Audio Works

Spatial audio works by leveraging advanced technologies such as Head-Related Transfer Function (HRTF) and object-based audio to create a personalized listening experience.

HRTF filters are designed to mimic the way sound interacts with the human ear, allowing listeners to pinpoint the location of sounds in 3D space. This means you can hear sounds coming from above, below, or around you, just as you would in real life.

Object-based audio takes this a step further by allowing sound engineers to place audio objects in specific locations within the sound field. This creates a more immersive and realistic sound environment, as each sound can be precisely positioned and moved within the 3D space.

Together, these technologies enable spatial audio to replicate the natural way we hear, providing a truly immersive audio experience.

Devices that Support Spatial Audio

A wide range of devices now support spatial audio, making it accessible to more listeners than ever before. Apple’s AirPods Pro, AirPods Max, and Beats Fit Pro are among the most popular devices that offer spatial audio support.

These devices use advanced algorithms and sensors to deliver an immersive audio experience. Beyond headphones, spatial audio is also supported by soundbars, home theater systems, and gaming consoles, allowing you to enjoy immersive audio in various settings.

Many modern smartphones and tablets also come equipped with spatial audio capabilities, enabling you to experience high-quality, immersive audio on-the-go. Whether you’re at home or on the move, there are plenty of options to experience the benefits of spatial audio.

The evolution of 3D audio from surround sound

Moving on, it is crucial to emphasise the significant differences that 3D audio offers compared to traditional audio formats such as stereo and surround sound.

Media content must be available in specific surround sound formats, such as 5.1 or 7.1, to function effectively with spatial audio, highlighting the compatibility requirements between spatial audio technology and traditional surround sound formats in enhancing the immersive listening experience.

“If you say you can move and hear the surround sound on one plane, front and back, the left ear and the right ear, then I would say Dolby Surround is two-dimensional. […] And only if I now start to be able to give height information to the object, then I would be in 3D in this area.”

This explanation focuses on how 3D audio creates an immersive environment and interactive listening experience through the introduction of height information and the consideration of head movements, which not only surrounds around the listener with two ears but immerses them directly in the soundscape.

The 3D Audio Matrix clarifies

The definition of 3D audio depends heavily on the context in which it is used. It’s a question that can be answered by my ‘3D Audio Matrix’ – a concept I developed to visualise the different aspects and applications of 3D audio. More about this on my blog and in my training course.

To create spatial audio content, various software tools like Spatializer and Dolby Atmos are essential. These tools allow users to manipulate sound in a three-dimensional space, positioning audio sources realistically in relation to the listener, enhancing immersion through virtual reality and leveraging technologies such as binaural recording and Head-Related Transfer Function.

In the world of three-dimensional sound, there is often a confusion of terms, which I address in my interview with Thomas Riedel.

“Many colleagues use Dolby Atmos and think they automatically create immersive audio. But many immersive media cannot be reproduced in the AC-4 format.”

It is crucial to understand the differences between spatial audio, 3D audio and immersive audio, as they each emphasize unique aspects of sound quality in the listening experience.

This clarity is necessary for users to fully enjoy hearing the advanced audio experiences that these technologies enable. When in doubt, you can rely on your ear – but here are a few definitions.

What is an immersive audio definition?

Immersive audio is an experience that allows you to immerse yourself in the sound itself, far beyond the limits of technology.

“Immersive audio can also be stereo”

is a realisation that emphasises that this type of audio experience is less about the number of channels or the complexity of the setup, and more about the feeling of immersion.

Personalized spatial audio enhances the listening experience by adapting audio playback to individual ear and head geometries, providing a more accurate representation of sound location.

A good song that gets you dancing in a club can be heard as just as an immersive experience as a complex multi-channel system. Immersive audio creates an atmospheric, immersive playback room-filling sound world that captivates the listener regardless of the technical realisation.

That’s why I find it critical when “immersive audio” is used as a synonym for “better” in an attempt to upgrade stereo and sell it at a higher price. You have to differentiate between immersive audio systems, or streaming platforms, i.e. technologies, and immersive content, services, i.e. experiences.

3D Audio: The spatial dimension of sound

The true depth of 3D audio is revealed in the ability to move the sound in all directions. In contrast to two-dimensional sounds, where the sound can only be moved on one horizontal plane, 3D audio opens up a world in which sound objects float vertically and envelop the listener.

Spatial audio replicates the human experience of sound in real-world environments, creating a realistic 3D soundscape that enhances immersion, spatial awareness, and emotional engagement.

“Only when I start to give height information to the object do we move into the realm of the three-dimensional. But even this kind of threedimensional sound is not enough.”

This dimensionality makes it possible to navigate in a sound sphere, to move towards or away from sounds, which is particularly important in the world of virtual reality and interactive games. This is where the concept of degrees of freedom quickly comes into play.

If I can rotate my head, this process is called dynamic head tracking and has three degrees of freedom of rotation. Apple’s headphones already make this possible.

Sounds crazy, right channel but this technology gives me five different playback options with my ears on these 3D Audio headphones. The blog article reveals more.

With six degrees of freedom, you’re in the world of gaming, XR, VR, AR and spatial computing. The movement in space works without sound processes such as Dolby Atmos but in game engines. Apple’s VR glasses, with the Apple Vision Pro Audio Features also enable translation to audio objects.

Creating Music for Spatial Audio

Creating music for spatial audio requires a different approach than traditional music production. Sound engineers need to consider the 3D sound field and strategically place audio objects to create a more immersive experience.

This involves using specialized software and plugins that support object-based audio mixing. By placing sounds in specific locations within the 3D space, musicians and producers can craft a more dynamic and engaging listening experience.

Additionally, the spatial audio format opens up new creative possibilities, allowing artists to experiment with innovative sounds and techniques. Embracing spatial audio technology can lead to the creation of truly unique and immersive musical experiences that captivate listeners in ways traditional stereo cannot.

Spatial Audio: Apple’s immersive audio systems

Apple has really understood and developed spatial audio. It has teamed up with Dolby Atmos, but this also causes a lot of confusion. Spatial sound is much more than Dolby Surround, which is ultimately a format that is only good for film and music.

Apple’s spatial audio, featuring binaural rendering and dynamic head tracking, enhances the listening experience by creating immersive 3D audio that adapts in real-time, making it accessible not only for music but across various media formats including gaming and movies.

They have presented a lot of features of the glasses, but it feels like all their computers have additional speakers with spatial audio built in. But when is three-dimensional really three-dimensional?”

I ask, pointing out that the use of 3D audio in a 360-degree video is different from that in music production or cinema.

On the Apple homepage, the term ‘Spatial Audio’ is used, while the German translation is ‘3D Audio’. This reflects not only a linguistic adjustment, but also Apple’s efforts to make this advanced audio experience accessible to an international audience.

“In German it’s ‘3D Audio’, and that suits us Germans who love numbers, data, facts,”

I suppose to emphasise the precision and clarity that the term ‘3D Audio’ brings to the German language. This terminological clarity helps to convey Apple’s revolutionary technology and emphasise its importance for an immersive listening experience.

I find “spatial audio” difficult in German and the sound effect produced is more reminiscent of delay and reverbs. Something from music production using classic audio formats.

Apple Spatial Audio

Apple combines object-based audio elements with spatial sound and ambient effects as well as independent stereo components to create a comprehensive spatial audio experience. The result is a listening experience that remains constant regardless of the viewing direction, which is particularly important for narrative voices or background music.

Producing and accessing spatial audio content is crucial to enhance listener experiences, especially on platforms like Apple Music and Netflix that support this immersive audio technology.

This approach makes it clear that spatial audio is not just one component of spatial sound, but an interplay of different elements perceive sound that together create different sounds and a truly immersive audio experience.

Read more about Apple’s spatial audio approach in the Realitykit here.

Here is the short summary:

• Object-based audio elements: Placement of sound objects in three-dimensional space so that listeners can perceive their position relative to the sound sources.
• Spatial sound and ambient effects: Addition of reverb and wall reflections to create a more realistic sound environment.
• Stereo without 3D audio: The ability to integrate stereo sound regardless of viewing direction, which is especially important for narrative voices or background music.

Apple Spatial Audio is not a real term. For me, it is simply an umbrella term for headphones, computers, etc., as. Software and hardware from Apple that does something with 3D audio.

How to Enable Spatial Audio

Enabling spatial audio on your device is relatively straightforward. For Apple devices, you can enable spatial audio by navigating to Settings > Music > Audio and selecting the “Spatial Audio” option. This will activate the feature, allowing you to enjoy immersive audio content.

On other devices, the process may vary slightly, so it’s a good idea to check the device’s settings or consult the user manual for specific instructions. Additionally, you can verify if your device supports spatial audio by looking for the “Spatial Audio” or “Dolby Atmos” logo on the device or within the settings menu.

Once enabled, you can start enjoying a richer, more immersive audio experience across your favorite content.

By following these steps, you can ensure that the new sections are well-integrated into the existing article, providing valuable information while maintaining a consistent tone and style.

Future and challenges of 3D audio

The future of 3D audio is undoubtedly promising, but it is not without its challenges. In the discussion with Thomas, it becomes clear that despite the impressive technological advances and growing interest in 3D audio, many people and media still struggle to navigate between the different audio formats and experiences available.

“Still, it’s a good sign that it’s getting more and more coverage.”

The industry is faced with the task of designing these advanced audio experiences so that they are intuitive and accessible without a listener having to wonder which technology is being used. It’s about creating seamless transitions between formats and ensuring that content is always of the best possible quality, regardless of whether it is presented in stereo, surround or 3D.

Knowing how to turn spatial audio on across various platforms and devices is crucial for listeners to fully appreciate and experience music and content as intended.

The onus is on both creators and consumers to develop a deeper understanding and appreciation of the subtleties of spatial audio. Enough theoretical definitions for today.

Looking for an expert who can also go into practice, whether for headphones or speakers? Then write me!