demo1.dat

it is lms algo based noise cancellation program. with the p4 256 mb ram, xp/vista/dos/linux platform

SETUP OF THE ACTIVE NOISE CONTROL EXPERIMENT


This program allows you to test a very simple active noise control
system at home. The purpose of this experiment is to demonstrate the
basic principle of active noise control, which is to cancel a sound
wave (noise) by emitting a secondary opposite (out-of-phase) sound
wave (control wave). In the real world, the implementation of active
noise control is much more complex due to frequency content of noise,
transducers efficiency, system identification, phase matching, etc...

Once you pressed the button "Continue", a new window will open and
the program will start sending a single frequency wave (sine wave
at 1000 Hz) to your right speaker. This sound wave represents the
noise to be cancelled. Take the time to adjust the volume so the
noise is relatively loud!! (If you have speakers with individual
volume adjustment, make sure the volume is the same on both
speakers). Then, by activating the control (clicking on the
"Start Control" button), the opposite sound wave is sent to the
left speaker. Setup the two speakers as shown on the drawing
(facing each other and close to one another). 
Now, you are ready to click on "Continue".


WARNING: This shareware and the accompanying files are given
"as is" and without warranties. VAL assumes no liability
for damages, direct or consequential, which may result from
its use.

NOTE: This shareware was tested using "labtec LCS-800" speakers;
the sound cancellation obtained was large and appreciable.
Note that the control results depend highly on the quality
of speakers used. Also notice that this experiment is more
impressive at medium-high volume (please be careful not to
saturate your speakers and ears).