effects of mobile telephones on hearing

the exposure to electromagnetic field emitted by mobile telephones is increasing rapidly worldwide that causes side effects, including thermal and non thermal side effects. ear proximity to electromagnetic source may lead to greater damage and side effects, including hearing loss. this study was performed to assess the chronic effect of exposure to electromagnetic field of mobile telephones on hearing by audiometric measurements. a total of 200 subjects (100 users and 100 non-users) were studied, using historic cohort method. the subjects did not have history of any clinical condition possibly implicated in hearing loss, history of ear disease or pathology in otoscopic examination. only the users dominant ears were studied (right side 75% and left side 25%). pure tone threshold of all subjects were in the normal range but there was a significant difference between mean pure tone threshold of user and non-users, +0.12 ± 5.93db and -3 ± 4.73db, respectively. duration of use was also related to threshold changes. this investigation showed that mobile sets may cause increase of the pure ton threshold. we suggest further studies to find out potential hazards of using mobile telephones and to develop guidelines for the mobile telephone users.