Phonetic fluency of Japanese learners of English: Automatic vs native and non-native assessment

Mariko Kondo, Lionel Fontan, Maxime Le Coz, Takayuki Konishi, Sylvain Detey

Research output: Contribution to journalConference articlepeer-review

3 Citations (Scopus)


This study compared automatic assessments of L2 phonetic fluency of Japanese learners of English in read speech, with ratings by native and non-native English assessors, and considers whether the first language of the assessors affects the results. Speech data of 183 Japanese and 25 native English speakers' readings of “the North Wind and the Sun” were assessed for phonetic fluency by 16 trained assessors with different first languages (four American English, four Japanese and eight other languages). They rated segmental accuracy, prosody, fluency and nativelikeness. A subset of 97 of the speakers' data (the 25 native English speakers and 72 randomly selected Japanese speakers) was also used to develop an automatic fluency assessment system. The 97 speakers' data were reassessed by four different trained American raters. The correlation between the automatic evaluation and the four raters was 0.83. When the automatic system was then tested on the remaining original 111 speakers' data and the original 16 assessors' scores, it showed correlations of 0.62-0.67 for the American, Japanese and other language raters. The results suggest that the automatic assessment system can assess phonetic fluency of Japanese-accented English quite reliably, and that native and non-native evaluators used different phonetic cues to evaluate fluency.

Original languageEnglish
Pages (from-to)784-788
Number of pages5
JournalProceedings of the International Conference on Speech Prosody
Publication statusPublished - 2020
Event10th International Conference on Speech Prosody 2020 - Tokyo, Japan
Duration: 2020 May 252020 May 28


  • Automatic assessment of speech
  • English learner corpus
  • Japanese accented English
  • Native assessment of speech
  • Non-native assessment of speech
  • Second language fluency

ASJC Scopus subject areas

  • Language and Linguistics
  • Linguistics and Language


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