Patent ID: 6795547
Filing Date: 2004-09-21
Classification: H04M

Abstract:
A speaker-phone that performs adaptive filtering on a speech signal, the speaker-phone comprising:a main control circuitry; a first adaptive frequency dependent attenuation circuitry communicatively coupled to the main control circuitry that performs adaptive filtering on the first speech signal using a first attenuation parameter; a second adaptive frequency dependent attenuation circuitry communicatively coupled to the main control circuitry that performs adaptive filtering on the second speech using a second attenuation parameter. a mode detection circuitry that detects an operation mode of de speaker-phone from among a plurality of operation modes, the plurality of operation modes comprising a receive mode, a double talk mode, a transmit mode, and a silence mode; and a real time modification circuitry that operates cooperatively with the main control circuitry and the mode detection circuitry to adjust the first attenuation parameter and the second attenuation parameter in real time in accordance with a transfer function defined by: &LeftBracketingBar;H&it;â€ƒ&it;(&ee;j&it;â€ƒ&it;Î©)&RightBracketingBar;2=(1-a)21-2&CenterDot;a&CenterDot;cos&it;â€ƒ&it;(Î©)+a2;0&leq;Î©&leq;Ï€.