Appeal No. 2003-2156
Application No. 09/849,761
The discussion at specification pages 4 and 5, and a
third example, recognizes that prior art squelching
operations applied to ADC converted audio signals for data
compression in MPEG (Moving Pictures Expert Group). In a
manner directly applicable to the claimed invention
utilizing plural bands of digital audio information, a given
digital audio signal is divided into multiple subbands by a
digital filter bank which has a threshold masking function
settable for each of the priority of frequency subbands. It
appears that this settability of the threshold level
corresponds to the ability to selectively mute and unmute or
selectively choose the allowable noise level for each
respective band. As explained at the top of page 5 of the
specification as filed, in any given band where the noise
level was outside (claim 14) of a given threshold masking
level, the signal was preserved and unmuted or not
attenuated in any manner. Correspondingly, in those bands
of frequency which were not outside of the threshold mask
level, that is, that were within (claim 14) the respective
threshold mask level value, the signal was attenuated. This
attenuation took the form of fewer bits of the comparable
6
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007