Soundproofing

Hi, I’d like to somehow make my voice not heard by the neighbors. I don’t sing but I need to somehow block my voice and hope that this community has an answer. I heard that pillows can help, so I recorded through my phone and tried to scream into/surrounded by pillows, and still could hear myself in the recording, Is there a way to block my voice better than the pillows did?

Also, I’m not planning on professionally soundproofing my room or something, I have zero budget lol. I know this question has been asked here before, but I couldn’t find any good answer, so thanks in advance!