# setActive:error: Activates or deactivates your app’s audio session. ``` - (BOOL) setActive:(BOOL) active error:(NSError **) outError; ``` ## Parameters `active` Use to activate your app’s audio session, or to deactivate it. `outError` On input, a pointer to an error object. If an error occurs, the framework sets the pointer to an object that describes the error. If you don’t want error information, pass in `nil`. ## Return Value if the system successfully changed the active state; otherwise . ## Discussion Your app may activate a session with category [`playback`](/documentation/AVFAudio/AVAudioSession/Category-swift.struct/playback) when another app is hosting a call, for example to start a `SharePlay` activity. However, your app isn’t permitted to capture the microphone of the active call. > Note: > If you attempt to activate a session with category ``doc://com.apple.avfaudio/documentation/AVFAudio/AVAudioSession/Category-swift.struct/record`` or ``doc://com.apple.avfaudio/documentation/AVFAudio/AVAudioSession/Category-swift.struct/playAndRecord`` when another app is already hosting a call, then your session fails with the error . The session fails to activate if another audio session has higher priority than yours (such as a phone call) and neither audio session allows mixing. Deactivating an audio session with running audio objects stops the objects, makes the session inactive, and returns an error. When your app deactivates a session, the return value is but the active state changes to deactivate. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)