Methods of selecting a number of channels for stimulation within a neural stimulation system include determining an amplitude of a multiplicity of stimulation signals each corresponding to a channel within a multiplicity of channels in the implantable stimulation system, using the amplitudes of the stimulation signals to determine a probability of each of the stimulation signals, and using the probabilities of one or more of the stimulation signals to randomly select a predetermined number of channels from the multiplicity of channels through which one or more of the stimulation signals are applied to a patient during a stimulation frame.