In part III under this title, fluctuations in electron trapping at semiconductor dislocations are analyzed. In this contribution these fluctuations of trapped charge are related to mobility fluctuations and reasonable agreement is found with the Hooge [F. N. Hooge, Phys. Lett. A29, 139 (1969)] expression for 1/fnoise. The calculated noise power is found to be proportional to the dislocation density and varies inversely with the doping levelNDat highND. We conclude from the analysis that the calculated frequency span of 1/fnoise from dislocations will only be wide if the dislocations are random; for aligned, impurity free dislocations a spectrum similar to generation‐recombination noise will be observed. Such behavior is observed experimentally.