In earlier works (Fan et al.), pressure fluctuations were measured only under steady-state conditions. The present work extends these earlier works to unsteady-state conditions induced by a step change in the flow rate. The resultant variations of the dispersion and distribution of the fluidized particles are correlated to the temporal variation of H (Hurst exponent) estimated for particles of various sizes and compositions fluidized at different flow rates. The approach and results of the present work should be useful for identifying and diagnosing both an upset in the operating conditions of a liquid-solid fluidized bed or deterioration in the performance of such a bed functioning as a contactor or reactor