There are people who have heard the unit and still say they can't hear anything. I was not referring to people who simply doubt it does anything given the lack of evidence.

It reminds me of a Simpson's sketch.. 'Mr. Hutz we've been in here for four hours. Do you have any evidence at all?'

'Hutz: Well, Your Honor. We've plenty of hearsay and conjecture. Those are kinds of evidence.'