Evaluation of excessive noise effects on hearing employing psychoacoustic dosimetry

Research results regarding the noise impact on hearing applying the concept of the Psychoacoustic Noise Dosimetry (PND) are presented. The general characteristics of the PND algorithm are discussed. Additionally, the results of hearing examinations conducted in the laboratory conditions are shown. The main objective of the research was to determine the time needed for the Temporary Threshold Shift to reverse. The results were used for the optimization of the designed PND performance. A validation of the PND algorithm was performed considering real noise exposure conditions. A new way of assessing noise-induced harmful effects on human hearing system was proposed employing the new indicators of noise harmfulness. The indicators are based on some psychoacoustical properties of the human hearing system and, simultaneously, on the time and frequency characteristics of noise. The correctness and the practical applicability of the newly proposed indicators were confirmed experimentally using hearing testing with real noise exposures and also on the basis of simulation results employing some standard test signals.