What about wall treatments? Yes, there are some effective ways to absorb sound by using certain kinds of wall coverings. Remember that sound bounces off flat surfaces and can cause it to amplify. So if you add some fabric to the walls, it can absorb the sound instead of sending it back into the room.
Tapestries and curtains are actually very good tools at reducing sound. And if you want, you can even go to a more industrial level and put foam wall coverings up, such as you might find in an actual recording studio. There is also sound proofing paint that can be applied. However, this paint tends to leave a heavy finish on the walls and has challenges when you are trying to tint it to any shade that isn’t a light pastel.
There are varying opinions as to whether this paint actually sound proofs. It may absorb sound somewhat. But you may need to apply layers, and considering the finished product is heavy and raised, it may not produce the desired visual appeal you are looking for. But it is an option, none the less.