I'm looking at some sound suppression.

I have a friend that has sensory input issues (autistic) and I’m researching some good sound suppression for her. I came across something by a company called Pro Ears and they have an inner ear solution that they are calling Audiomorphic.

Now to someone that’s not an audiophile all that means to me is that it’s some hybrid audio device. Do any of you know what it is and how it works? I mean without directing me back at the manufacturers propaganda page :)

<edit>  The reason that we're looking at passive noise cancelling is that she can't deal with the pink noise that results from ANC.  </edit>