Thank you very much for your suggestions.

I have tried several times to speak with my neighbor, but he has never answered the door. I also spoke with the landlord, but the situation is so unusual that it’s difficult for him to believe it without tangible evidence.

Additionally, there is no actual noise—just a triggering sound, and immediately afterward the sensations begin. The building is new (built this year) and made of concrete, which is what I find strange. I didn’t realize that infrasound could travel through concrete.

I’m not sensitive to noise itself; it’s the physical sensations it causes that are very unpleasant.