---
title: sourceGroups
framework: phase
role: symbol
role_heading: Instance Property
path: phase/phaseducker/sourcegroups
---

# sourceGroups

The sounds that determine volume reduction.

## Declaration

```swift
var sourceGroups: Set<PHASEGroup> { get }
```

## See Also

### Specifying Sounds

- [targetGroups](phase/phaseducker/targetgroups.md)