// Global variables
winrt::com_ptr<IAudioStateMonitor> g_audioStateMonitor;
AudioStateMonitorRegistrationHandle g_registration = 0;

// Returns true if the GameMedia stream is to be disabled, false if it's to be enabled.
bool IsSoundLevelMuted(_In_ IAudioStateMonitor* audioStateMonitor)
{
    return (audioStateMonitor->GetSoundLevel() == AudioStateMonitorSoundLevel::Muted);
}

HRESULT StartTrackingSoundLevel()
{
    // Create an AudioStateMonitor, and register for callbacks from it.
    HRESULT hr = RegisterForSoundLevelChanges();
    if (SUCCEEDED(hr))
    {
        // Check the current sound level, and determine whether the GameMedia stream is to be enabled.
        bool disableGameMediaStream = IsSoundLevelMuted(g_audioStateMonitor.get());

        // Here, add code that enables or disables the GameMedia stream 
        // according to the value of the Boolean.
    }
    return hr;
}

HRESULT RegisterForSoundLevelChanges()
{
    HRESULT hr = S_OK;

    // Create a new AudioStateMonitor for the GameMedia category, if needed, and register for callbacks.
    if (m_audioStateMonitor == nullptr)
    {
        hr = CreateRenderAudioStateMonitorForCategoryAndDeviceRole(
                 AudioCategory_GameMedia, ERole::eConsole, g_audioStateMonitor.put());
        if (SUCCEEDED(hr))
        {
            // Optional "context" parameter is not used in this example
            // and is set to nullptr.
            hr = g_audioStateMonitor->RegisterCallback(OnAudioStateMonitorCallback, nullptr, &amp;g_registration);
        }
    }

    if (FAILED(hr))
    {
        // g_audioStateMonitor is a smart pointer, so if an IAudioStateMonitor 
        // was allocated, then setting the smart pointer to null invokes the
        // Release method, which will decrement its usage count and ensure that 
        // the object is destroyed properly.
        g_audioStateMonitor = nullptr;
    }
    return hr;
}

// Unregister callbacks on program shutdown
void UnregisterForSoundLevelChanges()
{
    if (g_audioStateMonitor != nullptr)
    {
        if (g_registration)
        {
            g_audioStateMonitor->UnregisterCallback(g_registration);
        }

        // g_audioStateMonitor is a smart pointer, so setting it to null
        // will invoke the Release method to decrement its usage count.
        g_audioStateMonitor = nullptr;
    }
}

void OnAudioStateMonitorCallback(_In_ IAudioStateMonitor* audioStateMonitor, _In_opt_ void* context)
{
    bool disableGameMediaStream = IsSoundLevelMuted(audioStateMonitor);

    // Add code here that enables or disables the GameMedia stream 
    // according to the value of the Boolean.
}