What is immersive audio? Binaural, ambisonics and Atmos, explained.

Immersive audio is sound that surrounds the listener, including above and behind, instead of only coming from the left and right. It is also called spatial audio or 3D audio. It is used in music streaming, cinema, games, virtual and augmented reality, museums and live venues. The terms get mixed up a lot, so here is a plain guide to what they mean and how to choose.

Three ways to describe a sound scene

Channel-based audio

The classic approach. Each audio channel feeds one speaker: two for stereo, six for 5.1, eight for 7.1. It is simple and reliable, but the mix only plays back correctly on the layout it was made for.

Object-based audio

Sounds are stored as objects: audio plus metadata describing where each sound is in space and how it moves. A renderer then works out what each speaker or headphone should play at playback time. This is how Dolby Atmos works. It combines a channel bed with moving objects, up to 128 elements in total, and the same mix can play on a cinema system, a soundbar or headphones.

Scene-based audio (ambisonics)

Ambisonics captures or describes the whole sound field around a point, independent of any speaker layout. First-order ambisonics uses four channels. Higher orders use more channels, (order + 1) squared, so third order uses sixteen, and give sharper localisation. Ambisonics is easy to rotate, which makes it a natural fit for 360 video and VR, where the listener turns their head.

Binaural: 3D sound on ordinary headphones

Binaural audio uses HRTFs (head-related transfer functions), filters that model how your head and ears shape sound arriving from each direction. Applied to a sound, they make it seem to come from a specific point in space when played over headphones. Any of the three formats above can be rendered binaurally, which is how immersive music, games and VR reach people without special speakers.

Add head tracking, from a VR headset, a phone or supported earbuds, and the sound stays fixed in the world while the listener turns their head. That one feature does more for realism than almost anything else.

Immersive audio on speakers

Installations, domes, venues and museums often use many speakers around and above the audience. Panning techniques such as VBAP, or ambisonic decoding, spread each sound across the array. These systems must be tuned on site, because every room reflects sound differently and the audience moves around inside the sound field.

Which approach fits your project?

• Music for streaming and release: object-based mixing, typically in Dolby Atmos workflows, delivered alongside a stereo mix.
• VR, AR and games: an object-based spatial audio engine with binaural rendering and head tracking, often with ambisonic beds for ambience.
• 360 video: ambisonics, rotated with the viewer's head.
• Installations and venues: multichannel speaker arrays with object panning or ambisonic decoding, tuned to the room.
• Apps and products: binaural rendering on headphones, with speaker fallbacks.

Interactive immersive audio

The most powerful immersive audio is not just played back. It responds. Sounds can follow where visitors stand, react to touch, change with music, data or time of day, and move through a space in sync with visuals and light. This needs a real-time audio engine connected to sensors or to the rest of the show, and it is where audio software, sound design and engineering meet.

How DareDive can help

We build immersive and spatial audio software: spatial engines for apps and XR, ambisonic and binaural tools, and multichannel systems for installations and venues. We also design the sound itself. If you are planning something that should sound as big as it looks, tell us about it below.