专利名称：Method and apparatus for preprocessing of
an acoustic signal before speech coding
发明人：SCOTT, SOPHIE,NAVARRO, WILLIAM申请号：EP95401261.3申请日：19950531公开号：EP0685836A1公开日：19951206
专利附图：
摘要：The method involves input of an acoustic signal to a high pass filter. If theenergy (E2) of the high-pass filter output exceeds a certain fraction of the energy (E1) ofthe unfiltered signal, a first state is selected. If it is less, a second state is selected where
the signal is subjected to high frequency pre-emphasis. The modification does not occur ifthe filtered signal energy is less than a threshold. The state is changed if severalsuccessive signal frames indicate a state different to that previously determined. Acounter (32) is incremented when a comparator (27) indicates a different state and isdecremented towards zero when the same state is indicated. At a threshold value, theoutput state is changed and returns to zero.
申请人：MATRA COMMUNICATION
地址：50, rue du Président Sadate, BP 32 - Creac'h Gwenn F-29101 Quimper Cédex FR
国籍：FR
代理机构：Loisel, Bertrand
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