Apparatus and method for echo cancellation

A subband echo canceler for receiving a subband of a first audio signal and a second audio signal at a corresponding subband frequency, the second audio signal subband having echoes of the first audio signal subband, comprising:

• compensating means for generating an artificial echo based on the first audio signal subband in accordance with a variable coefficient transfer function;
• arithmetic means, coupled to said compensating means, for subtracting said artificial echo from the second audio signal subband;
• and
• control means, coupled to said arithmetic means, and said compensating means for determining whether to update coefficients of said variable coefficient transfer function by comparing an output of said arithmetic means with a masking threshold value of a psychoacoustic model at the corresponding subband frequency of the second audio signal subband.

A subband echo canceler for receiving a first audio signal and a second audio signal having echoes of the first audio signal, comprising:

• first analyzing means for dividing the first audio signal into a plurality of first subbands;
• second analyzing means for dividing the second audio signal into a plurality of second subbands, each of said second subbands corresponding to one of said first subbands in the frequency domain;
• at least one compensating means for receiving one of said first subbands and for generating an artificial echo based on said received first subband in accordance with a variable coefficient transfer function;
• at least one arithmetic means, coupled to said compensating means, for subtracting said artificial echo from one of the second subbands at the corresponding frequency as said first subband;
• and
• control means, coupled to said arithmetic means and said compensating means, for determining whether to update a coefficient of said variable coefficient transfer function by comparing an output of said arithmetic means with a masking threshold value of a psychoacoustic model at the corresponding subband frequency.