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US 8,478,597 B2Granted
Method and system for assessing pronunciation difficulties of non-native speakers
AssigneeEducational Testing Service
InventorsDerrick Higgins, Klaus Zechner, Yoko Futagi, Rene Lawless
Life of this patent
Estimating the term…
Abstract
The present disclosure presents a useful metric for assessing the relative difficulty which non-native speakers face in pronouncing a given utterance and a method and systems for using such a metric in the evaluation and assessment of the utterances of non-native speakers. In an embodiment, the metric may be based on both known sources of difficulty for language learners and a corpus-based measure of cross-language sound differences. The method may be applied to speakers who primarily speak a first language speaking utterances in any non-native second language.
Claims30
A computer-implemented method of assessing pronunciation difficulties of a non-native speaker, the method comprising:
- determining a plurality of different types of phonetic sources of pronunciation difficulties between a language of a non-native speaker and a second language, said determining including determining multiple types of sounds in the second language that cause pronunciation difficulties;
- assigning a weight to each phonetic source of pronunciation difficulty, the weight representing a measure of severity of the source of pronunciation difficulty;
- calculating using a processor a phonetic difficulty score, wherein calculating the phonetic difficulty score comprises calculating a product of a number of times the phonetic source occurs in an utterance of the non-native speaker and the weight of the phonetic source;
- calculating using the processor a language model score based on a sound comparison between the language of the non-native speaker and the second language, wherein the language model score is calculated based on a difference between a cross-entropy of the utterance with respect to a language model of the language of the non-native speaker and a cross-entropy of the utterance with respect to a language model of the second language;
- normalizing using the processor the phonetic difficulty score and the language model score;
- and
- calculating and outputting a metric from the normalized phonetic difficulty score and the normalized language model score, the metric providing an assessment of pronunciation difficulty.
4 more elements
A system for assessing the pronunciation difficulties of a non-native speaker comprising:
- a processor;
- and
- a processor-readable storage medium in communication with the processor, wherein the processor-readable storage medium contains one or more programming instructions for causing the processor to perform a method of predicting the pronunciation difficulties of a non-native speaker, the method comprising:
- determining a plurality of different types of phonetic sources of pronunciation difficulties between a language of a non-native speaker and a second language, said determining including determining multiple types of sounds in the second language that cause pronunciation difficulties;
- assigning a weight to each phonetic source of pronunciation difficulty, the weight representing a measure of severity of the source of pronunciation difficulty;
- calculating a phonetic difficulty score, wherein calculating the phonetic difficulty score comprises calculating a product of a number of times the phonetic source occurs in an utterance of the non-native speaker and the weight of the phonetic source;
- calculating a language model score based on a sound comparison between the language of the non-native speaker and the second language, wherein the language model score is calculated based on a difference between a cross-entropy of the utterance with respect to a language model of the language of the non-native speaker and a cross-entropy of the utterance with respect to a language model of the second language;
- normalizing the phonetic difficulty score and the language model score;
- and
- calculating and outputting a metric from the normalized phonetic difficulty score and the normalized language model score, the metric providing an assessment of pronunciation difficulty.
7 more elements
A non-transitory computer-readable storage medium for assessing pronunciation difficulties of a non-native speaker, comprising computer-executable instructions, which when executed cause a processing system to execute steps comprising:
- determining a plurality of different types of phonetic sources of pronunciation difficulties between a language of a non-native speaker and a second language, said determining including determining multiple types of sounds in the second language that cause pronunciation difficulties;
- assigning a weight to each source of pronunciation difficulty, the weight representing a measure of severity of the source of pronunciation difficulty;
- calculating using a processor a phonetic difficulty score, wherein calculating the phonetic difficulty score comprises calculating a product of a number of times the phonetic source occurs in an utterance of the non-native speaker and the weight of the phonetic source;
- calculating using the processor a language model score based on a sound comparison between the language of the non-native speaker and the second language, wherein the language model score is calculated based on a difference between a cross-entropy of the utterance with respect to a language model of the language of the non-native speaker and a cross-entropy of the utterance with respect to a language model of the second language;
- normalizing using the processor the phonetic difficulty score and the language model score;
- and
- calculating and outputting a metric from the normalized phonetic difficulty score and the normalized language model score, the metric providing an assessment of pronunciation difficulty.
4 more elements
Dependencies are inferred from the claim text.