Hmm ... AUDITORY, VESTIBULAR, AND OCULAR FUNCTION
A number of animal and some human studies have tested for potential effects of radio frequency EMFs on function and pathology of the auditory, vestibular, and ocular systems. Sub-millisecond pulses of radio frequency EMF can result in audible sound. Specifically, within the 200–3000 MHz EMF range, microwave hearing can result from brief(approximately 35–100ms) radio frequency pulses to the head, which cause thermoelastic expansion that is detected by sensory cells in the cochlea via the same processes involved in normal hearing. This phenomenon is perceived as a brief low-level noise, often described as a“click” or“buzzing.” For example, Röschmann (1991) applied 10-and 20-ms pulses at 2.45 GHz that caused a specific energy absorption (SA) of 4.5 mJ kg−1per pulse, and which was estimated to result in a temperature rise of approximately0.00001°C per pulse. These pulses were barely audible, suggesting that this corresponded to a sound at the hearing threshold. Although higher intensity SA pulses may result in more pronounced effects, there is no evidence that micro-wave hearing in any realistic exposure scenarios can affect health, and so the present Guidelines do not provide a restriction to specifically account for microwave hearing.