Mute nav on phone call

I have checked search and can't find anything on this for the Gen 3 ... any help is appreciated.

When I am on a bluetooth phone call while using nav, the nav voice is so loud that it interrupts the conversation. Is there a way to display nav (turn by turn) on the screen and HUD but mute the voice guidance for the duration of a phone call? Even turning off voice guidance entirely would be ok.

Thanks!