Hi guys, I am thinking of buying a second hand Garmin 276c. However, I am a little confused. The Garmin site states that the unit does not output voice prompts, yet it does have an output for a headphone jack/audio line out. A video on youtube shows a demonstartion of the system outputing voice commands so I am a little confused? Does this unit outout voice prompts or not? Any help much appreaciated. Wilson.