JBall is correct. Controlled listening tests can never be considered double-blind if the individuals choosing and setting up the listening test or have participants in the listening panel that have vested interest in the outcome. The whole idea of double-blind protocol and the whole purpose of adhering to this VERY strict scientific method is to try to control even the tiniest of bias whether unintentional/intentional as well as consciously/subconsciously from both the experimenter and its participants taking part in the study.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne