To improve my apartment acoustics while not making it ugly, I placed thin acoustic panels behind my wall-mounted world map. It is a pretty stealthy solution as the panels are only visible from the sides. I used double-sided adhesive tape to attach the light and thin panels. The foam is “acoustic molitan CME3535” from the Hornbach DIY store costing about $20, so it is probably not super high quality.
My goal was to reduce echos, ambient noises, and improve sound quality of my experimental podcast Reading Papers where I read usually ML related paper a day.
So I finally got to improving my apartment acoustics. Step by step as usual - not starting too dramatic. The panel foam quality is probably deficient, though.