High-Frequency Hearing Loss Amongst Smart Mobile Phone Users: A Case-Control Study.

Background: In past 20 years, there is increase in mobile phone users from 12.4 million to about 5.6 billion i.e 70 % of the world's population.[1] Electromagnetic radiations emitted from mobile phone damages inner ear, cochlea and outer hair cells of inner ear and auditory pathway (AP).[2].

Materials and methods: Case control study. Group 1, N=30 subjects, using mobile smart phones since past 1-5 years and exposure time more than 2 hours per day. Group II included 30 subjects, using mobile smart phones for more than 5 years and exposure time more than 2 hours per day. Headache, tinnitus, or sensations of burning around phone-using were excluded. Brainstem auditory evoked potential (BAEP) done. Student Unpaired t test was used for analysis and chisquare test.

Results: Mean ± SD of absolute latencies (AL) of Brainstem evoked response auditory. (BERA) waves III, V and all interpeak latencies at 80 dB and 4,6,8 KHz in group 2 were delayed and significant as compared to group 1. All parameters were highly significant at 8KHz as compared to 4KHz in group 2.

Conclusion: Brain stem evoked response audiometry (BERA) detects hearing loss in smart mobile phone using subjects at higher frequencies i.e at 8 KHz early. Hence central neural axis involvement can be detected early by BERA.