I came to the conclusion that my next door neighbor must be growing weed and it is his ventilation that is annoying me since November. I'm mad. I want to talk about this with him. Politely asking if he also hears this droning noise day and night. Asking and hinting if he has some kind of ventilation or air filter in use. I also bought a sound level meter for 130€ a few days ago, mostly because I wasn't aware of the possibility of him growing weed (due to recent circumstances and developments in my noise investigation and actions to solve something which is actually not the source of said noise), just getting evidence and frequency diagrams for my landlord so I could have a case for reduced rent. I don't hate him, I also don't hate smoking or growing weed, but I don't want to suffer while he's doing it.

 

What are my chances that if I tell him about the fact that I've been hearing a droning noise for some time now he will invest in better equipment/sound insulation? Involving the cops is not my plan, maybe some kind of ultima ratio if he's ignoring me or actively denying the sound or his involvement.