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1. 发明专利

JPH01123297A VOICE DETECTION CIRCUIT 失效
公开(公告)号：JPH01123297A
公开(公告)日：1989-05-16
申请号：JP28175387
申请日：1987-11-06
申请人： NIPPON TELEGRAPH & TELEPHONE
发明人： HOSOYA KATSUMI , DAI KEIICHI
IPC分类号： G10L11/00 , G10L11/02 , G10L15/04
摘要： PURPOSE: To detect a voice included in an input signal on conditions different by noise levels by updating a threshold in accordance with the noise level to decide sound/silence. CONSTITUTION: A voice signal is divided by a unit time, and an average power Pi of the section is calculated, and a certain value α is added to the average power Pi to calculate a value (Pi +α). The average power Pi and a threshold Ti are compared with each other to output a discridecision result X0 showing larger one. The calculated value (Pi +α) and the threshold Ti are compared with each other to output a discrimination result X1 showing larger one. This decision result X1 is inputted, and a threshold Ti+1 of the next section is set to Ti if (Pi +α) is equal to or larger than Ti , and the threshold Ti+1 of the next section is set to (Pi +α) if (Pi +α) is smaller than Ti . The threshold Ti is set to a preliminarily determined certain value T0 at the time of the start of operation and is changed to output the decision result X0 at each time of elapse of the unit time.

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