Sound echo canceller with loudspeaker function

Abstract

Abstract PURPOSE:To prevent a tape of an echo canceller from being corrected by a detour sound picked up by a microphone by controlling an echo canceller at a level of a reception signal from a remote end side before signal addition for loudspeaking. CONSTITUTION:At first, the sound signal Y picked up by a microphone is inputted to a subtraction circuit 93 through an amplifier 3 and an A/D conversion section 5. Then the subtraction circuit 93 subtracts an estimated echo signal Y generated by a filter 92 to output a residual signal E. Then the residual signal E is sent to a remote end through a D?A conversion section 7 and added to a signal received from the remote end by an adder circuit 11 through a variable attenuator 10. On the other hand, a sound detection section 12 detects the level of a reception signal from the remote end aud outputs a signal stopping coefficient correction to a coefficient correction section 91 when the level is below a prescribed level. Thus, the correction of the tap of the echo canceller is prevented due to the detour of a sound picked up by the microphone.

Inventors

• 👤 Tadasuke Maruyama
• 👤 唯介 丸山

Bibliographic Details