Apparantly a common problem.
My 760 randomly defaults to a non TTS (text to speech) setting. When it does, it won't speak the directions.
Solution from the Garmin Site:
This could occur if the voice
language has been de-selected. If you can hear the device produce a beeping noise then the voice
language needs to be changed or selected. If you do not hear any noise then the FM Transmitter might be selected or the sound has been Muted.
To check the voice
- Touch Tools
- Touch Settings
- Touch Language
- Touch the Voice option
- Touch on a selection that has TTS* in the description (example: American English - Jill - TTS)
- Touch OK
- Touch Back
The device should speak when in a route.
*Note - If the device is a 755, 765, 775, 785 then the selection will contain "Speaks Street Names" in the description.