Spatial Sound

Please read the Spatial Sound and Spatial Sound in Unity documentation for an overview of the concept and Unity Spatial Sound settings.

If you've ever played Marco Polo, or had someone call your phone to help you locate it, you are already familiar with the importance of Spatial Sound. We use sound cues in our daily lives to locate objects, get someone's attention, or get a better understanding of our environment. The more closely your app's sound behaves like it does in the real world, the more convincing and engaging your holograms will be. Spatial Sound does four key things for holographic development:

1. Grounding: Just like real objects, you want to be able to hear holograms even when you can't see them, and you want to be able to locate them anywhere around you. Just as holograms need to be grounded visually to blend with your real world, they also need to be grounded audibly. Spatial Sound seamlessly blends your real world audio environment with the holographic audio environment.

2. User Attention: People are used to having their attention drawn by sound - we instinctually look toward an object that we hear around us. When you want to direct your user's gaze to a particular place, rather than using an arrow to point them visually, placing a sound in that location is a very natural and fast way to guide them.

3. Immersion: When objects move or collide, we usually hear those interactions between materials. So when your objects don't make the same sound they would in the real world, a level of immersion is lost - like watching a scary movie with the volume all the way down. Spatialized sound make up the "feel" of a place beyond what we can see.

4. Interaction Design: In most traditional interactive experiences, interaction sounds like UI sound effects are played in standard mono or stereo. But because everything in HoloLens exists in 3D space - including the UI - these objects benefit from spatialized sounds. When we press a button in the real world, the sound we hear comes from that button. By spatializing interaction sounds, we again provide a more natural and realistic user experience.