How can I prevent my iOS VoIP app from playing audio when the user switches their phone to silent?

Question

I'm building a VoIP app on iOS and I'm using the AVAudioSession category of AVAudioSessionCategoryPlayAndRecord, which is recommended for VoIP apps that need to constantly play and record audio.

However, when the user switches their iPhone ringer to silent mode, the VoIP application will still play sound for an incoming call. This is not desired behavior.

Is there a way to prevent the incoming calls from playing audio when the user has their phone on silent, but still allow them to answer the call and have audio resume?

Answer 1

I think I found a solution that works for a VoIP application. If the phone is set to silent, I wanted the phone to show an alert and vibrate instead of playing the audible ring.

I can solve this by using local notifications and moving the sound out of the application and adding it to the notification itself. By specifying a sound file as part of the notification, iOS will handle whether it should play the audio or vibrate the phone. This is determined by the position of the Ring/Silent switch on the side of the phone.

Here's an Apple article on adding a sound to a local notification.