Since the sensitivity of the ear to sound is not the same for all frequencies, weighting or attenuating filters are included in the sound level meter’s circuits to simulate the ears’ response. A noise level meter gives an instantaneous measurement of the noise present, but cannot measure the duration of the exposure. To measure the amount of noise a person is exposed to over a period of time, a “dosimeter~ or an integrated sound level meter must be used. Sources for the above include the American Medical Association and the Canadian Hearing Society of Ontario. Decibel table developed by the National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892. January 1990.