Auditory Evoked Fields (AEF) elicited by stimulus of pure tones were measured from the lateral head of humans using a SQUID (superconducting quantum interference device). The waveforms of the magnetic fields had two opposite peaks at -100ms and -180ms latencies, and their maximum amplitude was -700fTp-p.
Current dipoles were assumed as the sources of the AEF, and their location, direction and moment were estimated from solutions of least-squares fit. The sources were estimated in the vicinity of the auditory area of right and left hemispheres with a moment of 3-30nA·m. The dipole moment estimated at the right hemisphere was larger than the dipole momoent at the left hemisphere.