Disaccommodation of initial permeability is normally measured after a ferromagnetic sample has been magnetized to saturation and subsequently pemagnetized. A technique has been developed for initiating reporducible disaccommodation in some nickel-zinc toroids after demagnetization from a level less than saturation. A theory, based on Néel's treatment, is presented which explains the experimental results on the assumption that behaviour is dominated by 180° domain walls. The work provides a basis for the study of the stability of soft ferrites subjected to small amplitude magnetic disturbances.