Research Of Mandarin Pronouncing Evaluation Based On Speech Recognition

With Chinese economy fast development, the communication between China and the world becomes more and more frequent in a wide range. Mandarin, the communication tool and culture carrier that lets the foreign country know China. Through analyzing traditional language education and existing researcher and tools and aiming to solve the common inaccurate pronunciation problem, we designed a pronunciation evaluation web system based on speech recognition, as an attempt in language education field. The speech recognition technique helps the learners have an accurate mandarin pronunciation. The tone recognition checks their pronunciation tones to make them know whether their tones are correct or wrong as mandarin tone is the most difficult issue confusing foreign learners. Our research is show as follows:1. We design and propose a tone recognition module, which is based on voice segmentation, applies SIFT method to extract pitch. A feature extraction algorithm with pitch normalization and improved neural network algorithm are presented.2. We set up a Speaker-Independent Isolated Word Recognition System, using MFCC and pitch as the feature parameter, taking initial/final as the recognition unit, adopting HMM with 32 Gaussian mixture components per state as the acoustic model. Finally, we get a system with the WER lower than 2.0% which basically meets the need of reliable interaction and pronunciation evaluation in practice.3. Based on the previous work, we improve the pronunciation evaluation method. Now it can evaluate the pronunciation more preciously.4. The system of Edutainment has been founded using Virtools. It can work online with the virtools'web player. The system includes virtual enviroment and some character models with animations. Some figure models in this system come from the Three-dimensional reconstruction fruits in our laboratory. We create a new speech recognition and pronunciation evaluation Building Blocks (BBs) as the speech interface using SDK of Virtools on VC++ 6.0 platform. It could provide the pronunciation information on initial/final level, helping students master their detail pronunciation information.