---
title: "init(engine:sourceGroups:targetGroups:gain:attackTime:releaseTime:attackCurve:releaseCurve:)"
framework: phase
role: symbol
role_heading: Initializer
path: "phase/phaseducker/init(engine:sourcegroups:targetgroups:gain:attacktime:releasetime:attackcurve:releasecurve:)"
---

# init(engine:sourceGroups:targetGroups:gain:attackTime:releaseTime:attackCurve:releaseCurve:)

Creates an object that manages competing sounds.

## Declaration

```swift
init(engine: PHASEEngine, sourceGroups: Set<PHASEGroup>, targetGroups: Set<PHASEGroup>, gain: Double, attackTime: Double, releaseTime: Double, attackCurve: PHASECurveType, releaseCurve: PHASECurveType)
```

## Parameters

- `engine`: The app’s instance of the framework object.
- `sourceGroups`: The sounds that determine volume reduction.
- `targetGroups`: The sounds that reduce in volume.
- `gain`: The volume level of the sound.
- `attackTime`: The amount of time for sound reduction to reach maximum strength.
- `releaseTime`: The amount of time to transition from maximum sound reduction to no reduction.
- `attackCurve`: A mathematical curve that shapes transition progress during the time it takes to reach maximum sound reduction.
- `releaseCurve`: A mathematical curve that shapes signal progress during the time it takes to transition from maximum sound reduction to no reduction.