Get a white noise machine. Put it next to the door or whatever wall you think the sound is coming through the most. It may sound loud to you at first if you've never used one of these before, but I promise you will get used to it and stop realizing it's there quickly.

This one is great for small spaces: https://www.amazon.com/Marpac-Machine-Non-Looping-Privacy-Therapy/dp/B07TK18KC2/ref=sr_1_8?crid=31QELNTG45NKE&keywords=white+noise+machine+for+adults&qid=1677399410&sprefix=white+noise+machine%5C%2Caps%2C100&sr=8-8