I left out one step in that protocol. Before the test starts, you have to play the test passage a couple of times both with and without the pad, but with the audiophile's knowledge. Once the audiophile agrees that he can hear a difference and that the test is working, then you can move on to the blind part of the test. All parties have to agree and be sure that the test is valid before you actually perform the test. If you don't, then the testee could come up with an after-the-fact excuse as to why he failed the test.

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Tony Fabris