AVAudioSession

AVAudioSession is Apple's framework-level gateway for configuring how your app's audio interacts with the device's hardware and other active apps.

To build a well-behaved audio app on iOS, iPadOS, or watchOS, you must coordinate with the operating system using AVAudioSession. This singleton object acts as the intermediary between your code and the system's audio engine: it defines your playback behavior through categories like playAndRecord or ambient, manages hardware route changes (such as a user unplugging headphones), and handles critical interruptions like incoming phone calls. By configuring the session's properties, you control whether your app silences background music or mixes with it, ensuring a seamless user experience across the Apple ecosystem.

https://developer.apple.com/documentation/avfaudio/avaudiosession