AbstractAudio‐sensitivity can be induced in strains of mice considered audio‐resistant by exposure to a brief auditory stimulation (60 sec at 95 db) at a critical age. Mice that had been audio‐conditioned were subjected to a battery of seizure‐evoking procedures and the responses interpreted in terms of neurophysiological mechanism. The effect of maturation on the development of sound induced, chemoshock and electroshock convulsion threshold and pattern was also studied. The pattern of maximal seizures induced by electroshock, pentylenetetrazol, and sound are remarkedly similar at a given age. The threshold for low frequency electroshock and for minimal pentylenetetrazol decreased with increased age and weight. There was no significant difference in maximal electroshock seizure threshold with aging, but duration of the seizure pattern markedly changed with increased age. Audio‐conditioning produced profound changes in the ontogeny of low frequency and chemoshock threshold, but maximal seizure threshold and pattern were unaffected. The audio‐sensitized CF# 1 mice differ in several ways from littermate. The oscillator mechanism of the audio‐sensitive mice is more easily discharged by electric and chemical stimulation, and there is an alteration in the neuro‐ontogenic pattern, and a decrea