We are more than happy to help if you are willing to describe the noise in more detail. Meanwhile please check out this thread . Post #37 describes the solution that solved my problem but you have to provide a much more detailed diagnosis if your noise is different. Is the noise speed or rpm, or road surface etc.dependent? Do you have a subwoofer installed in the boot/trunk (OEM or afermarket)? 24/7 means to me that you may hear it even if the car is stationary. Is it correct? Please take the time and provide as much information as possible.

 

 

OK, so now we know a lot more and your situation could be lot worse than I thought. The inverted polarity jump start must have fried some electronics. Now we know what is the cause of your problem but his issue cannot be solved or even diagnosed over the internet especially because it is audible even when the car is parked when all electronics are presumably shut down. You have to take the car to a knowledgeable (certified) car electrician and have him check your electrical circuits. ECUs (one or more) are the most likely candidates. We would only be able to guess and guesses that you need the least in this situation.
As a first step I would check all the fuses and relays in the engine bay and in the passenger compartment. You should try to pin-point the the exact location of the noise. It should not be difficult since the noise is present all the time, so you can do it while the car is parked.
Good luck!.