That was one thing I got figured out before my first I-Paces ceased up ... The Nav voice has her own volume. If you turn down the volume know while she's talking, that will only make her more quiet - and does not affect the rest of your music/media volume. In fact, if you look closely (again while she's talking), the volume level indicator bar on the screen changes color (I can't remember to what, but I think it goes from white to blue something) to try to indicate that she's got her own level. And, it will remember that for the future.