# Spatialized audio

<span class="label label-doc-level">Beginner</span>
<span class="label label-doc-audience">Designer</span>
<span class="label label-doc-audience">Programmer</span>

**Spatialized audio**, also called **3D audio**, simulates three-dimensional sound.
This creates more realistic audio than [non-spatialized audio](non-spatialized-audio.md). 

In real life, our experience of sound is affected by factors including its volume, the surrounding area (such as a cave or small room), and the position and movement of the sound source. We can usually tell approximately where a sound is coming from and whether it's moving.

![Spatialized audio](media/audio-index-spatialized-audio.png) 

For example, the frequency (pitch) of the sound coming from a moving object varies depending on the observer's position (the [Doppler effect](https://en.wikipedia.org/wiki/Doppler_effect)). Sound from an approaching source has a higher frequency than sound from a receding source:

![Doppler effect](media/audio-index-play-audio-doppler-effect.png)

To simulate realistic 3D audio, Stride tracks the positions of two entities in the scene:

* **[audio emitters](audio-emitters.md)**, which emit audio
* **[audio listeners](audio-listeners.md)**, which hear the sound emitted by audio emitters

You must have both audio emitters and audio listeners to hear spatialized sound in a scene.

Spatialized audio is widely used for sound effects in platform, desktop, and VR games. For example, a gun might make a gunshot sound when fired, or a character might make a footstep sound when they take a step.

> [!Note] 
> Spatialized audio uses more CPU than non-spatialized audio.

## Enable spatialized audio

When you [import your audio](import-audio.md), select *Spatialized Sound* as the asset type.

You can also set audio to spatialized in the asset's **Property Grid**:

1. In **Asset View**, select _Audio Asset_.

2. In the **Property Grid**, select the **Spatialized** checkbox:

    ![Select spatialized sound](media/audio-asset-properties-property-grid-spatialized-sound.png)

> [!Note] 
> Stride processes spatialized audio as mono (single-channel) audio. It doesn't alter the source file.

## See also

* [Audio emitters](audio-emitters.md)
* [Audio listeners](audio-listeners.md)
* [HRTF](hrtf.md)
* [Global audio settings](global-audio-settings.md)