You may need to mute (or unmute) notifications or the voiced turn-by-turn navigation for your Drive Smarter app. To do so, look for the Mute Notifications icon at the upper right of your screen.
Fig. A - Unmuted
This will cause notifications and turn-by-turn navigation to play on your phone. If your phone is connected via Bluetooth to a stereo system, notifications and navigation will play through device instead. If your phone is connected to CarPlay or Android Auto, audio will route there.
Fig. B - Muted
This will mute all notifications and navigation. They should not play over any audio system, phone, stereo, or through CarPlay or Android Auto.