Perceptual warping has been observed in various domains, both linguistic and non linguistic. The perceptual space is warped so that stimuli which belong to the same category are perceived as more similar to one another, while stimuli which belong to different categories are perceived as less similar to one another. Observations of perceptual warping in the linguistic domain have been confined to those of individual phonemes (for example, categorical perception of consonants, and the Perceptual Magnet Effect for vowels). This thesis attempts to replicate a study done by Dale Terbeek (1977) which may hint at perceptual warping caused by phonological classes of sounds. More specifically, this study trains English speakers on an artificial language with front/back vowel harmony. Similarity judgments of vowels are obtained before and after training to determine whether language training has warped the perceptual space. Results do not reach statistical significance, and recommendations for further study are made.