A SOUND ENGINEER

My neighbor is piping a low volume sound into my apartment that the private investigator that I hired could not detect. He's 64 years old. I need a good sound engineer to detect this noise. He pipes in a constant thumping noise and noise with an African beat to it. He can turn the volume up or down at will. He pipes this in throughout my whole apartment wherever he wants, even into the bathroom. It is deafening. It can not be heard over the telephone. He has even somehow managed to implant this sound into my car, which of course, the P.I. did not hear. This low volume sound is constant and being used day and night to keep me awake. Well, it's working. I don't know how he is doing this. I originally suspected the radiator, because that is where I first heard it when it started. That is also when I lost all heat to my apartment. Our apartments are side by side and we share a very very thin wall and floor. I have 4 months left on my lease, but I want to catch him before leaving.