Q:  I cannot detect any noticeable noise cancellation when I turn the unit on.
    The test situation is next to an exhaust fan on full and a running 
    dishwasher, both units produce a constant back ground noise. I cannot 
    detect any removal of noise from either the fan or the dishwasher by the 
    Noise Canceling Headphones.  In fact I can not detect any difference in 
    what I hear between when the headphone are turned on or when the
    headphones are turned off.  Is there a test procedure to verify that the
    headphones are working properly?

A:  Unplug the headphones. Do not place the bud far into the ear canal. Turn
    on the headphones (still unplugged from any audio source) and you should 
    hear the background noise being reduced. It should be similar to being 
    under water.

    Of course, please make sure that you have a 'fresh' AAA battery.
______________________________________________________________________________