[SWLUG] Noise abatement

[plebs.col at virgin.net]

  Is there  software or a device that will hear sound and generate the  
sound cancelling sound  so that sound presently attacking  can be  
cancelled?    The interesting thing is that the cancelling noise that will  
stop noise coming this way will confuse noise that has not got here  
yet.      Might persuade the generators to stop.

Anyone know what is being writ about and have suggestions?      There is  
some info in http://openlearn.open.ac.uk/mod/resource/view.php?id=285748

Any hope of a Jericho trumpet that will quarry stone?

Ilyan