Subband domain echo masking for improved duplexity of spectral domain echo suppressors

摘要

The present document relates to echo cancellation and/or echo suppression. In particular, the present document relates to a method and system for improving the perceived duplexity of handsfree telephone applications. An echo suppression circuit (202) for an electronic device (100) comprising a loudspeaker (107) and a microphone (105) is described. The attenuation circuit (202) is configured to attenuate a subband of a transmit signal (223), wherein the transmit signal (223) is captured by the microphone (105) and wherein the transmit signal (313) comprises an echo of a far-end signal (220) rendered by the loudspeaker (107) and a near-end signal (222). The attenuation circuit (202) is further configured to determine a subband far-end indicator of a voice activity in the far-end signal (220) based on the far-end signal (220) in the subband; determine a subband near-end indicator of a voice activity of the near-end signal (222) based on the far-end signal (220) and based on the transmit signal (223) in the subband; determine a subband masking weight, based on the subband far-end indicator and based on the subband near-end indicator; wherein the subband masking weight is indicative of a masking of the echo of the far-end signal (220) by the near-end signal (222) in the subband; determine a subband attenuation for the transmit signal (223) in the subband based on an estimate of a level of the echo of the far-end signal (220) in the subband and based on the subband masking weight; and attenuate the subband of the transmit signal (223) using the determined subband attenuation.