| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To remove an echo component in one's opposing party over a digital network. <P>SOLUTION: A multi-interface unit 12 is connected to an IP door terminal unit 16 via the digital network 20. At the side of the terminal unit 16, output sound of a speaker 24 is input into a microphone 26, and hence an echo component is generated. In this case, a sound signal x or y transmitted and received between the unit 12 and the terminal unit 16 is delayed by six buffers 30, 50, 52, 54, 34 and 36. An adaptive filter 32 performs adaptive operation, based on only a specified part after a lapse of prescribed time when delay time by the buffers 30, 50, 52, 54, 34 and 36 is considered, in the sound signal x input to the adaptive filter 32. Thus, echoes are canceled over the digital network 20 from the unit 12 to the terminal unit 16. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
