Considerable evidence exists for developmental changes in latency and amplitude of the auditory evoked potential termed N100. However, it is widely recognized that the N100 wave comprises multiple, temporally overlapping neural generators, and few data are available addressing either individual generator development or mechanisms behind such change. Using magnetoencelphalographic (MEG) measurements of the magnetic analog of the N100 termed the M100, which derives primarily from supra-temporal auditory generators, it is demonstrated here that changes in the response of that waveform to manipulation of interstimulus interval (ISI) occur between the ages of 6 and 18 years of age.