Has Speech on your Windows Phone gone mute?

One of my favorite new features in Windows Phone 7.5 is the option under Speech to have text messages read aloud.  I find this esepcially handy when I’m in the car, because I can listen and respond to text messages without ever taking my hands off the wheel or my eyes off the road.

I was puzzled,,however, when my HTC Trophy would periodically fail to read new messages.  I would hear the phone vibrate while driving  but nothing over the car’s sound system.  I checked the Bluetooth setting, and it was always on and connected.  I checked the settings for Speech, and it was set to read messages using Bluetooth and headsets.

I scratched my head about this for a few days before the light bulb finally turned on.  Remember I said I heard the phone vibrate?  If phone was set to only vibrate, no messages were read.  If the phone was set to vibrate and ring, it would read the messages. Apparently the ringer must be on for this feature to work, although I wasn’t able to find any documentation to that effect.

So what did we learn?  If your phone goes mute while you are driving, don’t worry.  Your driving hasn’t scared the phone silent. You probably just turned off the ringer.