There’s currently no native support for detecting whether or not the device ringer is set to silent. This poses an issue when you want to leverage the state of the ringer to trigger some action within the app, such as notifying the user.

Fortunately there’s a fairly straightforward way to detect this on your own using a system sound.

Detecting Ringer State by Playing a System Sound

When the ringer is on silent it prevents any system sounds you attempt to play from actually playing. Conversely when the ringer is not on silent the sound will play as expected. We can leverage this behavior to confidently determine whether or not the device is on silent based on how quickly our system sound finishes playing.

Add Muted Sound File to Resources

The first thing we need to do is obtain a copy of a sound file that doesn’t actually make any noise. Here’s one for convenience. After downloading the file add it to the Resources folder in your iOS project.

I added mine under Resources > Audio:

Write Code to Determine Playback Time of System Sound

Now that we have the file in place we need to create a System Sound and determine how fast the sound played.

The SystemSound object has an observer method called AddSystemSoundCompletion, which as the name suggests lets us know when the sound finishes playing. The idea here is simple: find the time delta between when the sound started playing and when it finished. If the difference in time is negligible than we can safely assume the ringer is on silent. However, if the time delta is closer to how long the sound file would typically take to play, it’s likely the ringer is not on silent.

The following method can be added to your view controller or other class that needs to detect the state of the ringer and take action:

public void IsMuted(Action mutedCheckComplete) {
    // create an instance of the SystemSound object, pointing to your "mute" sound resource
    var soundFilePath = NSBundle.MainBundle.PathForResource("Audio/mute", "caf");
    var mutedSound = new SystemSound(new NSUrl(soundFilePath, false));

    // capture the start time of the sound
    DateTime startTime = DateTime.Now;

    mutedSound.AddSystemSoundCompletion(() => {
        // find the delta between start and end times to determine if the sound played or was cut short.
        var endTime = DateTime.Now;
        var timeDelta = (endTime - startTime).Milliseconds;
        var muted = timeDelta < 100;

        // perform the callback to the invoker of this method, letting them know we have an answer.
        mutedCheckComplete(muted);
    });

    mutedSound.PlaySystemSound();
}

In my tests the time delta was very close to zero when the ringer was on silent, and closer to ~300ms when not on silent. In the above snippet I consider anything less than 100ms to be considered muted.

Now that the method is created we can invoke it whenever we need to check the status of the ringer. In my case, I use this in the ViewWillAppear method of my view controller. To avoid any unexpected lag between loading the UI and performing this check, I added the method call to the dispatch queue as follows:

DispatchQueue.MainQueue.DispatchAfter(new DispatchTime(DispatchTime.Now, TimeSpan.FromMilliseconds(100)), () => {
    IsMuted((muted) => {
        Debug.WriteLine($"Is Muted: {muted}");
    });
});

There we have it, a fairly trivial approach at determining the state of the ringer.

Sam Storino

Hi, I’m Sam.
I’m a programmer and a DIYer. When I’m not finding things to build I enjoy cooking, hiking, camping and traveling the world with my best friend. Say Hello!

www.storiknow.com