private func setupAudioSession() {
    do {

        try AVAudioSession.sharedInstance().setCategory(AVAudioSessionCategoryPlayback, with: .mixWithOthers)
        try AVAudioSession.sharedInstance().setActive(true)

        setupAudioNotifications()

    } catch {
        print(error)
    }
}

private func setupAudioNotifications() {
    NotificationCenter.default.addObserver(self, selector: #selector(handleInterruption), name: .AVAudioSessionInterruption, object: nil)
}

@objc func handleInterruption(notification: Notification) {

    guard let userInfo = notification.userInfo,
        let typeValue = userInfo[AVAudioSessionInterruptionTypeKey] as? UInt,
        let type = AVAudioSessionInterruptionType(rawValue: typeValue) else {
            return
    }

    if type == .began { // при звонке .began срабатывает всегда
        // Interruption began, take appropriate actions
        Player.shared.stop()

    } else if type == .ended { // а вот когда звонок заканчивается (любой из сторон), .ended не срабатывает
        if let optionsValue = userInfo[AVAudioSessionInterruptionOptionKey] as? UInt {
            let options = AVAudioSessionInterruptionOptions(rawValue: optionsValue)
            if options.contains(.shouldResume) {
                // Interruption Ended - playback should resume
                Player.shared.start()
            } else {
                // Interruption Ended - playback should NOT resume
            }
        }
    }
}