Noise Exposure Measurements in Real Ears: An Evaluation of MIRE-Technique Use in the Field and in the Laboratory

There are several sound sources and equipment used in information technology, which emit sound very close to the ear. The actual noise exposure of this equipment, communication hearing protectors and headsets for example, is difficult to evaluate through traditional methods. Therefore, new methods to evaluate noise exposure in real ears have been performed [1, 2]. The purposes of this study were to describe actual noise levels in the ear canal using measurements in real ears (MIRE-technique) and to evaluate the use of this technique in the field and in a laboratory. The measurements were carried out on snowplough car drivers and ice-hall workers, and also on volunteers in the noise laboratory. The personal daily noise exposures (L _Aeq,8h) varied between 76–90 dB for workers. A-weighted equivalent sound levels varied in the ear canal between 66 and 93 dB in the laboratory tests. According to the results of this study, a noise level correction of –4 dB was concluded for ear amplification. In the case of measurements placed in front of the ear canal, the A-weighted equivalent levels could be used without any correction.