G LearningLab | What is immersive audio? A closer look at formats and applications

Summary

In this episode of the Genelec Immersive Audio video series, Eric introduces viewers to the world of immersive audio, covering its definition, key formats, and where to experience it. The video explores popular formats like Dolby Atmos, Auro 3D, and MPEG-H, highlighting their use in cinemas, home theaters, broadcasting, and music production. Eric also explains the difference between channel-based and object-based audio, providing insight into speaker setups, production tools, and the evolution of audio formats. The episode serves as an informative guide to understanding immersive audio technologies and their applications in various industries.

Takeaways

• 😀 Immersive Audio refers to 3D or spatial audio, adding a third dimension of sound reproduction, often using ceiling or additional surround speakers.
• 😀 Immersive Audio is commonly experienced in cinemas, home cinemas, smart speakers, soundbars, and headphones.
• 😀 Two main concepts in Immersive Audio are object-based audio, where sounds can be placed freely, and channel-based audio, which uses a fixed array of speakers.
• 😀 Dolby Atmos is a widely used format that originated in cinemas, offering a hybrid system with both channel and object-based audio, and it’s increasingly popular in home entertainment and music.
• 😀 Auro 3D, another major format, uses up to three layers of speakers around the audience and is often used in cinemas, home theaters, and music production.
• 😀 MPEG-H, developed by the Fraunhofer Institute, is a flexible format used mainly in broadcast, and is the base for Sony's 360 Reality Audio format.
• 😀 Dolby Atmos in cinemas allows up to 128 audio tracks, with speakers placed throughout the theater, enabling highly immersive sound experiences.
• 😀 Dolby Atmos in home theaters offers setups with up to 22 speakers, with common configurations like 5.1.2, 7.1.4, and 9.1.6, enabling detailed sound design and content creation.
• 😀 Auro 3D uses a traditional surround setup (e.g., 5.1 or 7.1) and adds height channels to enhance the spatial experience, with speaker placement at a 30-degree angle.
• 😀 MPEG-H's interactive features, such as adjusting dialog levels or selecting different commentators in sports broadcasts, provide a personalized audio experience.
• 😀 Immersive audio formats use specific speaker layouts (e.g., 7.1.4 for Dolby Atmos), where the numbers represent speakers around the listener, with the ‘.1’ referring to subwoofers.

Q & A

What is Immersive Audio and how is it defined?

Immersive Audio, also known as 3D or spatial audio, introduces a third dimension of sound reproduction. This is achieved using multiple speakers, including ceiling speakers or layers of surround channels, to create a more immersive listening experience.

What is the difference between object-based and channel-based audio in Immersive Audio formats?

Object-based audio allows for precise control over sound placement by assigning coordinates to each sound element, enabling it to move freely around the listener. In contrast, channel-based audio relies on a fixed array of speakers, where sounds are panned across channels rather than being placed independently.

Where can Immersive Audio be experienced?

Immersive Audio can be experienced in cinemas, home cinemas, smart speakers, soundbars, and headphones. Its origin lies in cinema, but it has since expanded to home entertainment and music production.

What are some popular Immersive Audio formats?

Some popular Immersive Audio formats include Dolby Atmos, Auro 3D, and MPEG-H. Dolby Atmos is widely used in cinemas, home entertainment, and music, while Auro 3D is known for its channel-based setup and is used in cinema and music. MPEG-H is often used in broadcasting and supports both channel and object-based audio.

How does Dolby Atmos work in cinemas?

In cinemas, Dolby Atmos setups can include up to 128 inputs, with a combination of channel-based and object-based audio. This allows for precise sound placement, with speakers mounted in various positions, including ceiling speakers. Dolby Atmos systems can support up to 64 speakers depending on the room size.

What is the layout of a typical Dolby Atmos home cinema setup?

A typical Dolby Atmos home cinema setup can handle up to 22 speakers, with common layouts being 5.1.2, 5.1.4, 7.1.4, 9.1.4, and 9.1.6. These setups allow for immersive sound reproduction with both surround and height channels.

How does Auro 3D differ from Dolby Atmos in terms of speaker placement?

Auro 3D features ceiling speakers arranged in three layers, including a height layer mounted at 30 degrees. The system typically uses configurations like 9.1, 11.1, or 13.1, and includes a unique 'Voice of God' layer positioned directly above the audience for additional immersion.

What are some use cases for MPEG-H audio format?

MPEG-H is primarily used in broadcasting, such as in sports events where viewers can choose their preferred commentators, or in scenarios where viewers can adjust dialogue levels. It's also the foundation for the Sony 360 Reality Audio format, which targets music production and smart speaker playback.

How does the speaker layout in a 7.1.4 system work?

In a 7.1.4 system, there are seven speakers at ear level (surround channels), one subwoofer (.1), and four ceiling speakers for height channels. This configuration provides a balanced and immersive audio experience by placing sounds both around and above the listener.

What are the production tools for creating content in Dolby Atmos?

Production tools for creating Dolby Atmos content include audio workstations like Pro Tools, Nuendo, and Logic Pro, which can natively integrate Dolby Atmos metadata. Other DAWs such as Reaper and Ableton Live can use the Dolby Atmos music panner plugin to create Atmos content.