---
title: "start(completion:)"
framework: phase
role: symbol
role_heading: Instance Method
path: "phase/phasesoundevent/start(completion:)"
---

# start(completion:)

Invokes the sound event and runs the specified code on completion.

## Declaration

```swift
func start(completion handler: (@Sendable (PHASESoundEvent.StartHandlerReason) -> Void)? = nil)
```

```swift
func start() async -> PHASESoundEvent.StartHandlerReason
```

## Mentioned in

Playing sound from a location in a 3D scene

## Discussion

Discussion important: You can call this method from synchronous code using a completion handler, as shown on this page, or you can call it as an asynchronous method that has the following declaration: func start() async -> PHASESoundEvent.StartHandlerReason For information about concurrency and asynchronous code in Swift, see Calling Objective-C APIs Asynchronously. This function returns immediately after instructing the engine to invoke the sound event. If a problem occurs, the function provides an error. The sound event’s audio plays immediately if the app prepares the sound event in advance. Otherwise, the sound event begins preparing and then plays after preparation completes. When the sound event plays or errors out, the framework invokes completionHandler, passing in a PHASESoundEvent.StartHandlerReason that explains the reason for the invocation. important: To play the same sound asset again, create another sound event object. After the first start(completion:) call on a particular PHASESoundEvent instance, subsequent calls have no effect.

## See Also

### Starting Playback

- [PHASESoundEvent.StartHandlerReason](phase/phasesoundevent/starthandlerreason.md)