With Android Auto, every navigation prompt drops the music volume down to about 20%. It happens even after turning off "lower media volume during guidance" in both the car (MMI) and the navigation app. This ducking is caused by the phone's Android framework, not the car. On a Samsung Galaxy, a single toggle in Good Lock's Sound Assistant turns it off.
This document helps anyone with the same symptom (1) confirm the cause and (2) fix it on a Samsung phone. As of 2026-07, this was verified directly with adb shell dumpsys audio on a Samsung Galaxy S25 Ultra (Android 16 / One UI 8.5) + Audi A5 (2026, B10) + Android Auto (USB).
Since Android 8.0 (Oreo), when an app requests audio focus with AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK, the framework itself lowers other apps' volume. The attenuation is a fixed -14 dB (about 0.2 on a linear scale, i.e. 20%). The app does not adjust the volume — the OS steps in.
The navigation app requests this MAY_DUCK focus every time it plays a prompt, because Google's Android Auto navigation-app guide requires USAGE_ASSISTANCE_NAVIGATION_GUIDANCE + MAY_DUCK for guidance playback. So the navigation app follows the spec, and the price is forced framework auto-ducking.
The adb shell dumpsys audio event log records this exactly.
The navigation app requests focus on every prompt (req=3 = GAIN_TRANSIENT_MAY_DUCK):
07-13 22:28:57:337 requestAudioFocus() from uid/pid 10399/10098
AA=USAGE_ASSISTANCE_NAVIGATION_GUIDANCE/CONTENT_TYPE_SPEECH
callingPack=com.nhn.android.nmap req=3 flags=0x0
The framework ducks the music player from volume 1.0 → 0.2, then restores it when the prompt ends:
07-13 22:28:57:338 ducking player piid:20199 (com.apple.android.music)
usage=USAGE_MEDIA ... VolumeShaper.Configuration{ mDurationMs=500.0, mVolumes[]=[1.0, 0.2] }
07-13 22:29:04:133 unducking piid:20199
The ducking/unducking events line up 1:1 with the start and end of each navigation prompt.
Android Auto renders audio on the phone and streams it to the car over USB. Media and guidance go on separate channels, and the car mixes them. In the log above, the music is already reduced to 20% inside the phone, so the car receives audio that is already quieter. That is why touching MMI settings does nothing.
adb dumpsys audio shows the music player and the navigation-voice player rendering to different virtual outputs (deviceIds), and the Android Auto session (gearhead) activity window. Ducking is applied at the mixer (AudioTrack) level, so the media PCM leaving for the car is already attenuated.
Note that some cars add their own attenuation (double-ducking) when the guidance channel is active. But in this case, the phone-side ducking alone explains the entire symptom.
Apple Music does not handle ducking itself (it does not declare willPauseWhenDucked), so the framework auto-ducks it. By contrast, apps like Spotify detect focus loss and adjust their own volume, so framework auto-ducking does not apply and the behavior can differ. To isolate the cause, swap the music app and compare.
Samsung phones on One UI 7 or later have a framework flag (mIgnoreDuckingByNavigation) that ignores this ducking. It defaults to OFF. It can only be enabled through the Sound Assistant module toggle in Good Lock — adb settings put cannot change it (it is not a settings-DB key but an AudioService-internal setting).
How it works: if the app that took focus has usage USAGE_ASSISTANCE_NAVIGATION_GUIDANCE, local media ducking is skipped. That matches this case exactly (navigation usage = navigation guidance, music ducked locally).
Steps:
adb shell dumpsys audio | grep -i ignoreducking
# mIgnoreDuckingByNavigation=true means it is applied
Verify the effect (after a drive):
adb shell dumpsys audio > dumpsys_audio_after.txt
grep -E 'ducking player|unducking' dumpsys_audio_after.txt
If no ducking player ... com.apple.android.music event appears around the prompt, the phone-side ducking is resolved.
The
dumpsys audioevent ring buffer is not retained for long. Dump right after the drive so the ducking events from the prompt window are still present.
Caveat: community reports include cases where this toggle did not work in an Android Auto session (it depends on car and app combination). Still, when dumpsys confirms the ducking happens in the phone framework — as in this analysis — the toggle is likely to help. Verify it yourself with the steps above after applying.
mIgnoreDuckingByNavigation is a Samsung One UI-specific feature. Stock Android, other manufacturers, and iPhone (CarPlay) do not have this toggle. Android Auto (gearhead) itself has no setting to disable ducking, and as of 2026-07 there is no official Google fix. In those cases, switching to a music app that handles its own ducking (such as Spotify) is the realistic workaround.
This is not an Audi-specific problem. It is reported across many brands (Ford, Mercedes-Benz, Chevrolet, etc.) and many navigation apps (Naver Map, TMAP, etc.). Many user tests report "phone-only / Bluetooth playback is fine, ducking happens only over Android Auto," which matches the analysis above (the phone framework is the cause). It stems from the shared Android Auto projection architecture.
For another case of using adb to narrow down a different Android Auto problem, see Wireless Android Auto repeated disconnect diagnosis.