We study the temporal profile of the time-resolved four-wave-mixing signal in media with strong polarization interactions, assuming a stochastic modulation of the optical-transition frequency. The model is exactly solvable and interpolates smoothly between Lorentzian (fast modulation) and Gaussian (slow modulation) broadening. We show that recently predicted and observed four-wave-mixing signals persist even in the latter limit, albeit with a different temporal profile. © 1991 The American Physical Society.