How did a stimulus order in AX discrimination training influence improvement in the ability to perceive an American English /l‐r/ and /gl‐gr/ among Japanese listeners?

Previous research has shown that discriminability of /l‐r/ in AX discrimination may be significantly lower when /l/ is presented as the first stimulus than otherwise, among Japanese listeners under certain experimental conditions. The present study examined whether the stimulus order in AX discrimination training had significant effects on improvements of the ability to discriminate and identify English /l‐r/ and /gl‐gr/. One group of Japanese listeners (N=12) received twelve sessions of AX training in which stimuli (i.e., lexical items) were presented in the order of /l/ to /r/ (e.g., glock‐rockh), while the stimulus order was reversed (e.g., grock‐lockh) in the other (N=12). A comparison of pre‐test and post‐test results found the former group showed a significant improvement of the ability to discriminate /l‐r/ (p=0.037), to identify /l/ in /l‐r/ (p=0.023), and a significantly better‐defined category boundary of synthetic /la‐ra/ stimuli than the other group in the post‐test (p=0.05), while none of the...