While many had their hearing ability impaired after working in hazardous condition for years, many young generation today are suffering premature hearing damage after exposing to prolonged high volume of portal music player. Apple Ipod for example can produce up to 104db of sound and those who play such music player in noisy surrounding may need to turn up the volume to drown the external noise in street condition or in public transport. According to H.E.A.R., maximum exposure to 105db should be limited to 1 hour. Hence owner of MP3 players are cautioned on turning down the volume when listening to music via ear set and limit the length of each hearing session.
Link to H.E.A.R as below :