Individuals generalize differently depending on the extent of their past experiences and what they learn from them. For instance, the peak of generalization can shift from a familiar stimulus to novel ones when the familiar stimulus has been repeatedly discriminated from something similar. We examined how the amount of experience students had in discriminating complex sounds impacted their later generalization. As training increased, participants improved at distinguishing sounds, but their tendency to respond to certain novel sounds increased. With additional training, however, this shift dissipated. The results suggest that shifts in generalization may correspond to transitional states of perceptual learning and that learning-related changes in perceptual sensitivities involve more than just incremental increases in feature selectivity.