Magnetoencephalographic studies of auditory system function.

Magnetoencephalography (MEG) has provided a noninvasive method of demonstrating physiological processes underlying fundamental aspects of auditory system function. MEG technology offers a key advantage over evoked potentials, that being a relatively unimpeded view of structures underlying auditory evoked responses in which cortical sources predominate. Investigators conducting auditory evoked field investigations have demonstrated tonotopicity, amplitopicity, and periodicity pitch representation in the auditory cortex. This article provides a description of MEG, various auditory evoked fields that have been reported, the psychophysics associated with auditory evoked field component N1m, and some clinical applications of this technology.