Well I'm not a consultant but what you are probably looking for is a dB meter and I would guess there's not really any reason to measure frequencies other than curiosity. If you are considering measuring frequency because you know that human ears are less sensitive to certain frequencies then consider using a meter with an A-weighted option.
A Weighting
The most common weighting that is used in noise measurement is A-Weighting. Like the human ear, this effectively cuts off the lower and higher frequencies that the average person cannot hear.
Also, you may want to consider using a Noise Dosimeter that will keep track of noise exposure throughout a period of time.