Development of a computer-assisted language learning system utilizing a speaker adaptation and a grammatical error modeling

利用说话者适应和语法错误建模开发计算机辅助语言学习系统

• 批准号: 16300260
• 负责人: ITO Akinori
• 金额: $ 5万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16300260/
• 关键词: Language learning system; Pronunciation evaluation; Prosody evaluation; Interactive CALL system; Speaker adaptation; Grammatical error model; Intonation; Rhythm; 決定木; n-gram; 誤り訂正モデル; 発音誤り検出; 音素環境; 機械学習; 文法誤り検出; SSTコーパス; CALLシステム; 音声認識

1. Improvement of Pronunciation EvaluationWe developed a method to detect pronunciation mistakes made by a foreign language learner by applying a speech recognition technology. We focused on the following two targets: learning of English by Japanese native speakers and learning of Japanese by Korean native speakers. To improve the accuracy of detection of mispronunciations, we developed a bilingual speaker adaptation method to adapt both of English and Japanese HMMs to the learner. To solve a problem that the strictness of the detection of mispronunciations depends on the linguistic context of the pronunciation, we developed a method of detecting mispronunciations using a decision tree, which gave a detection accuracy of more than 90% on English utterances made by Japanese native speakers.2. Evaluation of Intonation and RhythmIn addition to the detection of mispronunciations, we developed methods to evaluate intonation and rhythm of the English utterances. We found that the log F0, log power and their derivatives were good features for the evaluation of intonation. To adjust the strictness of intonation evaluation from word to word, we introduced a method to estimate the word importance factors using a decision tree. We also found that a word duration ratio was a good feature for rhythm evaluation.3. Development of an interactive CALL systemWe developed a method of detecting grammatical errors from utterances of a learner for the application to an interactive CALL system that enables for a learner to learn a foreign language through dialogues with a computer. As for the learning of Japanese, we developed a method to recognize the learner's speech using a finite state automaton to which grammatical error rules were applied. As for the learning of English, we developed a method to use an n-gram language model trained from a corpus that was automatically generated using the grammatical error rules.

1.发音评估的改进我们开发了一种通过应用语音识别技术来检测外语学习者所犯发音错误的方法。我们关注以下两个目标：日本母语者学习英语和韩国母语者学习日语。为了提高错误发音检测的准确性，我们开发了一种双语说话人自适应方法，以适应英语和日语的HISTORY学习者。为了解决发音错误检测的严格性依赖于发音的语言背景的问题，我们开发了一种使用决策树的发音错误检测方法，该方法对日语母语者的英语发音的检测准确率超过90%.语调和节奏的评估除了错误发音的检测，我们还开发了评估英语话语语调和节奏的方法。我们发现，对数F0，对数功率及其衍生物是很好的评估语调的功能。为了调整语调评估的严格性，我们引入了一种使用决策树来估计单词重要性因素的方法。我们还发现，词的持续时间比是一个很好的特征的节奏评估。交互式CALL系统的开发我们开发了一种从学习者的话语中检测语法错误的方法，用于交互式CALL系统，该系统使学习者能够通过与计算机的对话来学习外语。至于日语的学习，我们开发了一种方法来识别学习者的语音使用有限状态自动机的语法错误规则。至于英语的学习，我们开发了一种方法，使用从使用语法错误规则自动生成的语料库中训练的n-gram语言模型。