Cinel C, Boldini A, Russo R, Fox E (2007):
The authors carried out this study as part of the UK's Mobile Telecommunications and Health Research Programme. The study was planned in response to a small study by Maier et al. in 2004, which suggested that an auditory discrimination task was impaired after RFR exposure for 50 min. However, that study involved only 11 subjects.
In the present study there were 168 participants, of whom 84 were exposed to an 888 MHz CW signal and the other half to an 888 MHz GSM signal. For each group 42 participants were tested with a mobile phone positioned on their left ear, and the remaining 42 had the phone on the right ear. The subjects were tested in 2 sessions. They were presented with 2 identical sounds at narrow intervals from stereo headphones, one in the left and the other in the right, and had to identify which ear the first sound came from. The interval was initially 240 ms, and was decreased if the response was correct and increased if it was incorrect. This task was performed at the beginning of the session, and was followed by an interval of 40 min, during which they were either exposed to RFR from a mobile phone, or were sham-exposed. The task was then repeated. The average SAR was 1.4 W/kg. For the GSM mode the peak SAR was 11.2 W/kg. The order of the exposure was randomized, as was the order of the sounds i.e. the ear that received the first sound.
The auditory threshold was the minimum interval necessary for the subject to achieve an accuracy score of at least 69%.
The order threshold was smaller when the task was performed at the beginning of the session than at the end, but this was independent of whether the subjects were RFR- or sham-exposed. No significant effect of RFR exposure was seen in other situations tested i.e. CW versus GSM or left versus right ear.