This paper presents an improved Voice Activity Detection （VAD） algorithm which uses the Signal-to-Noise Ratio （SNR） measure. We assume that noise Power Spectral Density （PSD） in each spectral bin follows a Rayle...This paper presents an improved Voice Activity Detection （VAD） algorithm which uses the Signal-to-Noise Ratio （SNR） measure. We assume that noise Power Spectral Density （PSD） in each spectral bin follows a Rayleigh distribution. Rayleigh distributions with its asymmetric tail characteristics give a better description of the noise PSD distribution than Gaussian distribution. Under this asstlmption, a new threshold updating expression is derived. Since the analytical integral of the false alarm probability, the threshold updating expression can be represented without the inverse complementary error function and low computational complexity is achieved in our system. Experimental results show that the proposed VAD outperforms or at least is comparable with the VAD scheme presented by Davis under several noise environments and has a lower computational complexity.展开更多
The aim of the article is to present results of research that was performed with 97 Polish students of the second and third year of English Philology. The purpose of the research is to examine how conscious manipulati...The aim of the article is to present results of research that was performed with 97 Polish students of the second and third year of English Philology. The purpose of the research is to examine how conscious manipulation of facial expressions aids acquisition of foreign vowels by learners, regardless of their native language and the culture they have been brought up in. Taking advantage of achievements derived from such disciplines as psychology of emotions and phonetics depicted as a physical process, an attempt is made to find a tool that improves teaching/learning of foreign vowels, that is to say, an effort is put in search of a useful method to make the phonetic process faster and more accurate. Teachers of English are encouraged to put the method, which is described in detail in the paper, into practice with their own mother languages and to share opinions about the method with colleagues. Similarly, it is believed that it can be applied to courses of other languages than just English. Teachers of those languages are encouraged to try to use it, too.展开更多
基金Supported by the National Natural Science Foundation of China (No. 60874060)
文摘This paper presents an improved Voice Activity Detection （VAD） algorithm which uses the Signal-to-Noise Ratio （SNR） measure. We assume that noise Power Spectral Density （PSD） in each spectral bin follows a Rayleigh distribution. Rayleigh distributions with its asymmetric tail characteristics give a better description of the noise PSD distribution than Gaussian distribution. Under this asstlmption, a new threshold updating expression is derived. Since the analytical integral of the false alarm probability, the threshold updating expression can be represented without the inverse complementary error function and low computational complexity is achieved in our system. Experimental results show that the proposed VAD outperforms or at least is comparable with the VAD scheme presented by Davis under several noise environments and has a lower computational complexity.
文摘The aim of the article is to present results of research that was performed with 97 Polish students of the second and third year of English Philology. The purpose of the research is to examine how conscious manipulation of facial expressions aids acquisition of foreign vowels by learners, regardless of their native language and the culture they have been brought up in. Taking advantage of achievements derived from such disciplines as psychology of emotions and phonetics depicted as a physical process, an attempt is made to find a tool that improves teaching/learning of foreign vowels, that is to say, an effort is put in search of a useful method to make the phonetic process faster and more accurate. Teachers of English are encouraged to put the method, which is described in detail in the paper, into practice with their own mother languages and to share opinions about the method with colleagues. Similarly, it is believed that it can be applied to courses of other languages than just English. Teachers of those languages are encouraged to try to use it, too.
