I can only imagine the nightmare that presenting this in court will be.
In my old job we had guys who specialized in analyzing noise and increases in noise due to projects. There is a whole science behind it and it is not just taking a noise reading and getting some decibel reading.
As someone pointed out above, what is the baseline? How what percentage of the decibels are coming from the "offender"?
Lawyer 1: "Officer, what training have you had to "interpret" these readings?"
Officer: "Uhhh...I read the manual"???
I would much rather find the offending house, car, etc...shoot the distance with a lazer from where I can clearly hear the music, explain that XXX neighbors from YYY distance have complained, explain how loud the music is from within say about 50 feet of the house and call it good.