In order to differentiate the effect of noise during acquisition from the effect of system noise during production alone, the effects that both deficits have on speech production after asymptotic learning (i.e., learning was completed) were investigated as control conditions. In this case, the deficits were introduced only after training the model (i.e., after the developmental trajectory was fully completed at the baseline condition and the feedforward commands had been acquired without any deficits implemented; all noise levels at 0%) during production attempts in the performance stage. The same set of 27 sound targets was used, and each sound target was repeated 6 times.