1. A computer-implemented method of assessing spontaneous speech pronunciation, comprising: performing speech recognition on digitized speech using a non-native acoustic model trained with non-native speech using a processor to generate word hypotheses for the digitized speech; performing time alignment between the digitized speech and the word hypotheses utilizing a reference acoustic model trained with native-quality speech to associate the word hypotheses with corresponding sounds of the digitized speech; calculating statistics regarding individual words and phonemes of the word hypotheses using the processor based on said alignment; calculating a plurality of features for use in assessing pronunciation of the digitized speech based on the statistics using the processor; calculating an assessment score based on one or more of the calculated features; and storing the assessment score in a computer-readable memory.
1. A computer-implemented method of assessing spontaneous speech pronunciation, comprising: performing speech recognition on digitized speech using a non-native acoustic model trained with non-native speech using a processor to generate word hypotheses for the digitized speech; performing time alignment between the digitized speech and the word hypotheses utilizing a reference acoustic model trained with native-quality speech to associate the word hypotheses with corresponding sounds of the digitized speech; calculating statistics regarding individual words and phonemes of the word hypotheses using the processor based on said alignment; calculating a plurality of features for use in assessing pronunciation of the digitized speech based on the statistics using the processor; calculating an assessment score based on one or more of the calculated features; and storing the assessment score in a computer-readable memory. 12. The method of claim 1 , wherein one or more of the features are utilized with related stress, intonation, vocabulary, or grammar to generate the assessment score indicating communicative competence or other construct of speaking proficiency that includes pronunciation proficiency.