Prevent music volume from being lowered when using turn-by-turn navigation I use a Nexus 6 on Lollipop.  Sometimes I'll try to listen to music over Bluetooth while using Google Maps turn-by-turn navigation in my car.  The volume on the music is reduced whenever Google Maps gives the next turn, which is irritating.  I changed the settings in Google Maps to output using the device's speaker, but it still lowers the media volume over Bluetooth to give me turn information.

Is there any way -- ideally without needing root privileges -- to prevent this from happening?
From what I've read elsewhere, this functionality is generally handled by the application playing the music/audio. So, I've been testing out various players, and found a couple that do what Casey is requesting, MX Player and Poweramp. 

MX Player is primarily known as a video player, but it can also handle a number of audio formats (including Opus, which I happened to be looking for).

One drawback with MX Player is that it can't create dynamic playlists, so you have to have the songs ordered in folders to play in succession.

The other one that does what Casey is requesting is the music player app Poweramp, which lets you choose in its settings, under Audio->Audio Focus->Short Audio Focus Change, between no ducking (unchecked), and pausing (checked). Poweramp isn't free, though. 

Another app, Rocket Player, is a music player that will let you choose between ducking and pausing, but will not allow you to disable it completely, which is what Casey is looking for. (The setting is under Settings->Sound->Audio Focus->Temp Focus Action)

For myself, I've found that, especially for audio books and podcasts, I actually prefer pausing to ducking or no ducking, so I like Poweramp or Rocket Player for this purpose.