Automatic assessment of pronunciation quality

Learning to speak a foreign language is not an easy task for many people. This paper describes approaches to automatic objective assessment of pronunciation quality. The approaches described here can be classified into two categories, text-dependent and text-independent, according to whether a teacher´s voice is present. In the text-independent one, algorithms based on energy and pitch contour are introduced. Also, the average rate of variation in energy and pitch frequency, mean subtracted energy and pitch frequency are used as main features. Compared to the previously reported approach using average phone segment posterior probabilities, the new approach achieves favorable performance on the same test set.