Not getting "Intruder Alert" voice or beeps when Sensor triggered

I set my Ring alarm to 'Home' mode when I go to bed. This morning my wife got up and normally when one of the sensors is triggered we get a voice alert that says something like "Intruder alert" and a beeping that gives her time to switch the alarm off. This morning the alarm just went off with none of the above. Any ideas why or if there is a setting that needs to be reset to reactivate this?  Thanks