Inquiry About Background Volume Button Event in iOS App Development

I’m working on an iOS app for a client, and I have a question regarding a specific feature we're looking to implement.

We want the app to respond to a user pressing the volume button three times while the app is in the background. The goal is to allow users to discreetly trigger a safety feature without drawing attention, particularly in situations where they may be in danger or at risk.

This feature is critical for the app and would be a valuable addition, as it could potentially help protect users in emergency situations. However, I haven’t found much information on whether iOS allows background listening for volume button presses. Therefore, I would greatly appreciate your insights on the following:

Is it possible to listen for volume button presses when the app is in the background, or are there system-level restrictions that prevent this?

If it's not directly possible, are there any special provisions, APIs, or entitlements that can be requested from Apple to enable this functionality?

In case this feature is not supported, are there alternative approaches to achieve a similar discreet activation mechanism?

If this is something that requires special permission or a process, could you please guide me on how to proceed?

I understand that maintaining user privacy and security is a priority for iOS, and I want to ensure that any implementation fully complies with Apple's guidelines.

Thanks in advance for your help!

Hello @apptechfromnull, thank you for your post. To be able to listen for button presses in the background, your app needs to support one of the background execution modes. There is a limited number of them, and your app also needs to adhere to one or more of the prescribed use cases.

From an implementation standpoint, listening for volume button presses can be accomplished by key-value observing the outputVolume property of AVAudioSession. In addition to that, you can use the AVCaptureEventInteraction class to respond to capture events from system hardware buttons. Please also refer to the Enhancing your app experience with the Camera Control for a discussion on how to respond to activation state changes of the Camera Control on iPhone 16 devices.

Inquiry About Background Volume Button Event in iOS App Development
 
 
Q