Hi guys!
Since Kodi 17 I suffer from an annoying bug/feature: I hear a high frequency tone after playing a movie (with multi channel sound).
My setup: RP3 (running OSMC) <–HDMI–> AV Receiver <–HDMI–> TV
Kodi audio is configured with “Audio pass-through” and “adjust PLL” (don’t know if that is related).
<= Kodi 16 (no issue):
Kodi starts. AVR shows “PCM” and two little symbols “L” “R” for stereo sound.
If I start e.g. a movie with surround sound, AVR shows “Dolby Digital” and “L” “C” “R” “SL” “SW” “SR”.
When the movie comes to the end and stops (I see Kodi GUI), the AVR shows again PCM and “L” “R”.
> Kodi 16 (I tried 17.x till current 17.3):
Kodi starts. AVR shows “PCM” and two little symbols “L” “R” for stereo sound.
If I start e.g. a movie with surround sound, AVR shows “Dolby Digital” and “L” “C” “R” “SL” “SW” “SR”.
When the movie comes to the end and stops, the AVR shows again PCM, but NO “L” “R” symbols.
I could live with that 
But: I also hear a continues very high frequency tone.
I can fix that by just starting the movie again and then manual stopping. AVR returns to PCM and “L” “R” (+no abnormal sound).
What I already tried:
I noticed the new option in Kodi 17 “send low volume noise”. I disabled that, but with no success.
Also I played arround with PLL from “low” to “high” without any change.
I guess something must have changed in the way Kodi handles the end of the movie and returns to the GUI. Because manually stopping a movie doesn’t suffer from that problem.
Debug log (provoking the issue): https://pastebin.com/raw/8zj4Whsk
Any advice would be highly appreciated. If you need further information, let me know.
Best regards,
Casper