DEVELOPMENT OF RESISTANCE TO NOISE

Recent investigations have demonstrated that in animal models repeated exposures to mid-intensity noise induce a progressive reduction of th e temporary threshold shift (TTS) following the exposures. This phenom enon is named ''conditioning'' and it is actually able to reduce the p ermanent threshold shift (PTS) following exposure to high intensity no ise; this finding is named ''toughening''. In the present work the fun damental steps of the research concerning the toughening are reviewed and the biological mechanisms supposed to be underlying this phenomeno n discussed. The few preliminary results of the studies on humans are also reported.