Source modelling of neuromagnetic responses evoked through auditory stimuli. (a) The response showed an activity peak at 45–150 ms. (b) Typical magnetic field patterns of the peak in the auditory cortex. The magnetic field strength is indicated by a coloured line, which varies from green (flux-in) to red (flux-out). Sensor locations are indicated by small dots. Black arrows indicate the directions of equivalent current dipole orientation. Blue open circles indicate the examples of the 30 sensors for each hemisphere (left and right) to estimate the current sources. A, anterior; P, posterior; L, left; R, right.