Binaural hearing in the presence of a low frequency magnetic field

The authors propose the binaural auditory system as a candidate neural system that may be disrupted by exposure to relatively weak LF magnetic fields. Extracellular currents, induced by time-varying magnetic fields, may change the timing of action potentials in the auditory nerve, thereby disrupting sound localization when interaural time differences are very small. Three subjects were exposed to a 1,000 Hz magnetic field - with a maximum rate of change of 2.3 T/s at the location of the cochlea - while presenting two identical 1,000 Hz tones randomly delayed to the left or right ear by less than 10 /spl mu/s. The subjects were asked whether the signal was perceived to be displaced to the left or right side of midline. After a total of over 20,000 trials, conducted at different phase angles between the field signal and the tones, there was no clear evidence for a consistent change in performance when the magnetic field was present. This, however, does not rule out an effect at other combinations of magnetic and acoustic frequencies.<
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