The Study of Abnormal Voice Recognition in a Wafer-Coating Environment

• Main Authors: JUNK-KUEI PAN, 潘榮貴
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/9brkv3

碩士 === 國立臺灣科技大學 === 電機工程系 === 95 === The research target of this thesis is to establish an abnormal voice recognition system in a wafer-coating environment; The thesis focuses on setting up the abnormal voice recognition system which will not be interfered easily with by the sounds of the environment. The main research includes the management of the environmental voice in the beginning stage, and the voice feature established by the band-pass filters which is designed adapting to the abnormal voice differences. On the beginning stage of the recognition system, we intend to reduce the environmental sound by spectral subtraction. Regarding to the remaining spectral power problem, we propose the way of a smooth learning environment sound, and utilizing the spectral change amount in a sound frame to reduce spectral power, in the meantime increasing the spectral resolution capability. The voice feature is obtained by a band-pass filters. We adapt the setting of every frequency band center and bandwidth in the band-pass filters by the differences in frequency characteristics of the abnormal voice. According to the experimental result,band-pass filters designed by the method of this thesis have better results resisting the interference of other undesired signals. It uses less resources and easier calculation than the existing method. Through the experimental result, combine spectral subtraction improved and with the band-pass filters which are designed adapting to the abnormal voice differences, can be effective inhibition the environment voice and broad-band noise, and recognition the abnormal voice. At experiment, when we join Gaussian of broadband noises of SNR 4dB to -5dB to make uproar to the abnormal voice, the correct rate of distinguish abnormal voice can keep above 90%.