All participants were taken up for several audiologic investigations including pure-tone audiometry, speech discrimination score, speech reception threshold, impedance audiometry, distortion product otoacoustic emissions (DPOAE), auditory brainstem response (ABR) and middle latency response tests.
|Reference group 1||control group: never used mobile phones|
|Group 2||duration of mobile phone use: 1 - 2 years, < 60 min/day|
|Group 3||duration of mobile phone use: 1 - 2 years, ≥ 60 min/day|
|Group 4||duration of mobile phone use: 2 - 4 years, < 60 min/day|
|Group 5||duration of mobile phone use: 2 - 4 years, ≥ 60 min/day|
|Group 6||duration of mobile phone use: > 4 years, < 60 min/day|
|Group 7||duration of mobile phone use: > 4 years, ≥ 60 min/day|
|Reference group 8||control group: never used mobile phones: ≤ 30 years old|
|Group 9||mobile phone users: ≤ 30 years old|
|Reference group 10||control group: never used mobile phones: > 30 years old|
|Group 11||mobile phone users: > 30 years old|
There was no significant difference between users and non-users of mobile phones for any of the audiologic parameters. However, trends for audiologic disturbances were seen within the users. Risk factors could be age over 30 years, mobile phone use for more than 4 years and more than 60 min/day, presence of tinnitus or ear warmth during mobile phone use. The authors concluded that long-term and intensive mobile phone use may cause inner ear damage.
The results should be interpreted with caution as a large sample size is required to reach definitive conclusions.