Hazard a guess , were you thinking 1st , 2nd and 3rd generation IR(Infra Red) and 640pixel res. video output from an IR monoacle?
Also for around $500 you can get a bionic ear device(glorified way of saying super sensitive directional microphone).
There are companies in Sydney Australia have such technology available imported from the USA,the other half of it is for checking fires and circuit boards e.t.c.
Here's there general idea(i need to find the companies page again):
http://thehottestgadgets.com/2008/07/15-incredible-do-it-yourself-gadgets-001171