Research On Speech Recognition Algorithm And Application

With the development of technology, various appliances come in our houses, which are enriching people's lives and reducing the burden of people's lives. How to manage these appliances more effectively so that they can give us better services for our lives has become a hot issue. For this problem, the paper proposes the appliances can be controlled using the technology of speech recognition, and constructs Appliance Control System.This paper thoroughly studied basic principles of speech recognition, which contins Pre-processing, Feature extraction, Training, Recognition. In the process of Pre-processing, the original input speech signal was followed by the treatments of Pre-filtering, Pre-emphasis, Windowing, Endpoint detection and so on; In order to reduce the redundancy of information, speech signal must be followed by feature extraction, and Mel frequency cepstral coefficients (MFCC) was chosed as the feature parameters; Continuous Density Hidden Markov Models (CHMM) was chosen as the acoustic model of the acoustic unit, and the CHMM-based isolated word speech recognition algorithm has been developed.Studies show that the recognition accuracy of CHMM-based speech recognition algorithm decreased significantly, in noisy environment. To this defect, the paper proposed a new speech recognition algorithm, which was compensated in three levels of signal space, feature space, model space. The algorithm combines the advantages of Wiener Filtering, Histogram Equalization, Vector Taylor Series, and has better robustness, so it is called "the hybrid robust speech recognition algorithm".Taking TMS320VC5402 as the core chip,the writer constructed memory circuits, speech signal acquisition circuits, LCD display circuits and wireless transceiver circuits of Appliance Control System, which realized management of TV, DVD, refrigerators, air conditioners, washing machines, lights and other appliances.The results show that: in interior noise environment, the recognition rate of the appliance control system is 98.00% by the hybrid robust speech recognition algorithm, which reached the purpose of this subject.