Gargoyle

               DSP +"echo canceliing"
               DSP +"noise cancelling"

Starting here may be useful

http://www.dsprelated.com/

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_____________________________________

DSP noise cancelling project group
2006 page - may stilll be active

            http://www.dsprelated.com/showmessage/56897/1.php

Worth copying here. Sounds like just what you want.

_________________________

Hey everyone, I'm new to this forum.

I am working with a group of Virginia Tech EE undergraduate students doing
our senior project. We are designing a digital controller for noise
canceling headphones. We have a pair of headphones equipped with an
internal microphone. We've done initial testing of our system, and
designed our controller. The transfer function is 4th order. Here it is:

Zero/pole/gain:
0.15321 (z^2  + 1.248z + 0.7911) (z^2  + 0.2258z + 0.8837)
----------------------------------------------------------
    (z^2  - 1.207z + 0.3842) (z^2  - 1.568z + 0.7318)

Sampling time: 8e-0

We have a ADSP-2181 EZKit and are trying to implement this transfer
function with the board. We are looking for any help in figuring out an
easy way to program the board to achieve this transfer function.

I know very little about this board, but have read some stuff on how to
program specific filters. These sites specifically:

http://www.ee.iastate.edu/~dickerson/classes/ee424/lab/lab1/LAB1A.html
and this pdf
http://www.ece.rutgers.edu/~orfanidi/ezkitl/man.pdf

Any help is appreciated!
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