Training Japanese listeners to identify American English vowels

Perception training of phonemes by second language (L2) learners has been studied primarily using consonant contrasts, where the number of contrasting sounds rarely exceeds five. In order to investigate the effects of stimulus sets, this training study used two conditions: 9 American English vowels covering the entire vowel space (9V), and 3 difficult vowels for problem‐focused training (3V). Native speakers of Japanese were trained for nine days. To assess changes in performance due to training, a battery of perception and production tests were given pre‐ and post‐training, as well as 3 months following training. The 9V trainees improved vowel perception on all vowels after training, on average by 23%. Their performance at the 3‐month test was slightly worse than the posttest, but still better than the pretest. Transfer of training effect to stimuli spoken by new speakers was observed. Strong response bias observed in the pretest disappeared after the training. The preliminary results of the 3V trainees ...