Sound pressure level (SPL) meters are used to measure sound or noise and usually provide dbA and dbC measurements. If you are in a room and there is no difference between the dbA and dbC reading it means? A. There is a large amount of low frequency sound (i.e., rumble) in the room. B. It means the meter is working properly. C. It means the meter need calibrating. D. The amount of high and low frequency sounds are about the same