Why Doesn't My Phone Make a Notification Sound?

The two platforms both respect the settings of the operating system when it comes to deciding what different scenarios do or don't cause the notification to make a sound. We provide a sound for the notifications, but can't guarantee that it will be heard in all cases as the operating system is responsible for this decision.

For example, a participant may turn their volume down but keep their vibration setting on. In this case when a notification prompts on their device, the sound would not be heard, but the vibration would. Alternatively, If the volume is up and the vibration is off, the phone will make a sound but not a vibration.