Average rating score (with standard deviation) of accentedness for each talker rated by 105 native English-speaking college students. The talkers were rank-ordered from low to high in accentedness rating. The first two were native English talkers. The remaining 24 were native Mandarin talkers learning English as an L2. The four talkers marked with arrowheads were selected as the accented talkers to produce sentence stimuli for the perception task.