Originally Posted By: ClubNeon
Originally Posted By: Dave B
How is it double blind if one person is clearly able to tell a difference when he sets the speaker?

Double blind studies are used to rule out actual differences from prejudice.

If you don't know the how's and why's, here's the short of it.

The "double" means both the tester and testee, are unaware of which sample is being tested. Or if the tester does know there's no way for that information to be communicated to the testee (that means no forms of communication between the two, not even non-verbal forms like body language).

The two samples are presented. The testee is then tasked with identifying each one uniquely after each switch. If he is only correct around 50% of the time, then it is just chance. But if one sample can be identified a majority of the time, then there is a difference.

Two very difference speakers will obviously be able to be identified uniquely.


I understand how double blind studies work. But if the listener is blind and his assistant is rotating the speaker (which is all that is necessary in this application), it's not double blind; it's just blind. The person changing the variable, which in this case is simply the speaker position, is not blind. [Nor does he need to be.] He can't be, unless the speaker is a perfect square.

If it was an A/B speaker test that could be toggled via the use of a single button, that'd be double blind, of course... but that'd introduce positioning/room effects since the presence of one speaker could change the sound of the other slightly.