The use of a personal noise dosimeter to measure the daily exposure of a worker to noise was discussed. Such dosimeters have been designed to be worn by a worker. The dosimeter can compute, store, and display accumulated noise dose. Such data were used for compliance purposes in survey work. The device had a microphone which may be extended to a worker's ear or hearing level. Most dosimeters have been designed to integrate noise exposures over a given period of time into a single noise index displayed as a percentage of the permissible noise exposure. The accuracy of nine common dosimeters was tested regarding 111 different categories: frequency response test, cut off level test, shifting levels test, rise and decay time, exponential formula accuracy test, dose storage test, integration accuracy test, crest factor/square law test, 115 decibels-A slow latch test, foldover test, and additional tests conducted in the presence of magnetic fields, variations in ambient temperature and variations in atmospheric pressure. The author indicates that when purchasing a noise dosimeter it is important to consider self containment, other physical characteristics, accessories and potential problems.