5. Misc & Misused
What does it mean when we say that an audio experience is 1D, 2D, or 3D? The interchangeable use of word ‘dimensions’ to refer to different things can be confusing, especially when the concept being referred to usually has its own name.
One way we’ve heard ‘‘dimensions’’ expressed is to illustrate the difference between mono, stereo, and spatialised or binauralised audio, where 1D refers to mono, 2D refers to stereo, and 3D refers to spatial audio. Perhaps you’ve even hear 4D, which likely either refers to time or spatial audio in 6DoF (your sensors detect depth / forward, backwards, and side-to-side motion). This relates to #DegreesOfFreedom and #DynamicSpatialAudio.
The word ‘Dimensions’ has also been used to express when height information is included in audio spatialisation. For example, we’ve heard spatialised audio that only take yaw and pitch into account expressed as 2D spatial audio, which would therefore mean that spatialised audio with yaw, pitch and roll is 3D spatial audio.
Video games and any other experience created in a video game engine will likely use game-object based audio. Though the industry evolves quickly, this is still the most straightforward way people work with audio in video games. Video game engines such as Unity or Unreal can be created in 3D or 2D.
In case it hasn’t already been made clear, using dimensions to express spatial affordances is very confusing, so we recommend staying away from these terms.
Related Terms : Degrees of Freedom (DOF)
3D audio as a term can often be found used in marketing campaigns where zero spatial audio is happening and there is no for of interactivity such as head-tracking or movement. This raises some questions about market intelligence and can lead to issues where specific features or even projects are misunderstood technologically by consumers due to the varying level of expectations thrown around for the terms such as “3D Audio” or even “Spatial Audio”.
3D Audio has been used as a term to describe any of the following:
- headtracking and interactive spatial audio
- headlocked room modeling processed audio
- HRTF specific processed audio (headlocked)
- HRTF processing for object audio (headtracking)
- Binaural effect processed headlocked stereo (similar to non-technical terms like
- Binaural recorded headlocked stereo audio
- Roomscale game object audio processing
- Roomscale spatial pre-rendered audio processing
As the list grows it is becoming more clear that when someone refers to 3D Audio or Spatial Audio it can really mean anything, leading to miscommunications and pain points for both creatives and consumers.