Towards an Automatic Foreign Accent Reduction Tool

An automatic tool to reduce foreign-accent is described and evaluated. An unaccented speech utterance was used to improve three prosodic features of a corresponding foreign-accented utterance. The duration, pitch and intensity of the foreign-accented speech utterance were modified using DTW (Dynamic Time Warping), WSOLA (Waveform Similarity Overlap Add), and other automatic speech processing algorithms. The modified speech utterance was then evaluated to determine the perceived foreign accent compared to the original. Fifteen native speakers of American English took part in the perceptual test to rate the degree of foreign-accent in Korean-accented American English. The results show that the modified Korean-accented utterances were perceived to have a lower degree of foreign-accent than the original Korean-accented utterances. 1