Appeal No. 2002-1197
Application 09/131,167
a first threshold or above a second threshold. Because Koski
does not have predetermined thresholds, as claimed, it does not
teach or suggest that one of the predetermined threshold values
is adjusted to account for analog compression. Although Koski
may detect double talk to prevent distortion, this does not
suggest keeping the output signal below or above a threshold
value to account for analog compression. The rejection of
claim 30 is reversed.
Claims 38-41
The issue is whether the combination of Koski and Haneda
discloses or suggests "means for updating filter coefficients of
said adaptive filter only when an absolute value of the output
signal of the microphone is less than a saturation constant"
(claim 38). Unlike claims 1, 13, 17, and 25, claim 38 positively
limits the updating of coefficients when the output is less than
the full range of the output signal and, as discussed in
connection with the rejection of claim 1, this is not taught by
Koski. The rejection of claims 38-41 is reversed.
Requirement under 37 CFR § 1,196(d)
The specification describes that "practical experience" has
demonstrated that adaptive filtering techniques do not work well
when the source signal (e.g., the near-end microphone signal)
becomes saturated. Specification, p. 3, first full paragraph.
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