PC Speaker "echo" sound on my Steam Deck while playing Commander Keen 1

[Gagert]

I'm having a somewhat weird issue when running Commander Keen 1 in the dosbox-core libretro core on my Steam Deck. As soon as I start a new game, there's some kind of PC speaker echo sound that can be heard after Keen moves, both on the map screen & inside the levels. I have only experienced this issue on my Steam Deck.

I have the very same setup for RetroArch 1.19.0, libretro cores & games/roms installed on both my Windows 11 PC, Android phone, Android tablet and Steam Deck. For my Steam Deck, I have the Flatpak release of RetroArch 1.19.0. I'm using dosbox-core 27b6dbe with RetroArch on my Steam Deck. This issue occurs both when launching RetroArch via desktop mode and within the Steam Deck frontend itself (under "non-Steam" games). As mentioned above, I have not experienced this audio issue on my other devices using the very same config for this game.

I use the same configs for this game & the dosbox-core for all my devices, the dosbox-core config I use here is attached to this post in a zip archive.

KEEN1 cfg.zip

My DOSBox-core.cfg file only has the following line:

aspect_ratio_index = "2"