My NAV works well, but the other day I noticed that after the directions began, the volume was so low I could barely hear it. I called dealer and they told me to adjust the audio volume control as the voice is speaking directions, and that should fix it. I was listening to a CD at the time and must have adjusted the volume of the CD while the NAV was "speaking" and set it lower without knowing.

Duh, seems so simple and it worked.

 

Yep...I first found out about that little function with my wife's former CLK550 back in '07. You gotta catch it just in time before she quits speaking to raise or lower the volume.