Larry Dighera wrote:

That's not what it says he
http://www.garmin.com/products/gma347/

The GMA 347 audio panel builds upon the successful attributes of
the GMA 340
snip

The GMA340 certainly has this feature. I use it all the time in my
Bonanza. If the 347 is built upon the successful attributes of the GMA340,
then Garmin most likely included this feature in that unit as well.

--
Peter