Measuring foreign accent strength in English : Validating Levenshtein distance as a measure

With an eye toward measuring the strengths of foreign accents in American English, we evaluate the suitability of a modified version of the Levenshtein distance (LD) for comparing (the phonetic transcriptions of) accented pronunciations. Although this measure has been used successfully inter alia to study the differences among dialect pronunciations, it has not been applied to study foreign accents. Here, we use it to compare the pronunciation of non-native English speakers to native American English speech. Our results indicate that the Levenshtein distance is a valid native-likeness measurement, as it correlates strongly with the average "native-like" judgments given by more than 1000 native American English raters (r = -0.8, p < 0.001).