How to have the radio auto mute when Nav is speaking?

[LexusStephen]

Can the radio be set to mute when the navigation system is giving instruction?

[1990LS400]

1 hour ago, LexusStephen said:

Can the radio be set to mute when the navigation system is giving instruction?

I've always wondered why muting the audio system during a navigation instruction on Toyota/Lexus navigation systems isn't an option  ... but it's never been.

I've gotten used to pressing the MAP buttons in our vehicles to have the last navigation instruction repeated.  Sometimes I first manually mute or lower the audio system volume.