"So you deny that knowing the measurements before listening may cause bias?"
You are asking a loaded question as to say, "if measurements can bias listening tests, let me use my eyes just as well to do my listening tests." Answer to that is that if you know such biases exists, then you better not do any sighted listening tests.
On my end, when such knowledge can create corrupt outcomes, then I don't even do the listening test. Example is DACs. Unless distortion is very high, I don't do sighted listening tests.
In other cases, measurements provide incredible value in creating the proper listening test. If for example I know from measurements that a headphone amplifier has trouble driving low impedance headphones, I use that information to drive a such a headphone with content specifically designed to push that corner of fidelity.
For speakers/headphones, it goes without saying that we can tell the difference between them so blinding is not needed on that front. What I do in my listening tests there is to use the measurement as a guide to see if I can improve the response using EQ. If I can, then I publish that EQ for others to try as well. Knowing measurements there is therefore a wonderful tool just as it is for your doctor.
People who claim they should listen first and measure second, just have it wrong. They will then be giving you a random subjective opinion in a sighted test with no reliability factor. Who is to say their ears tell the truth? Or that the speakers are setup in the way that the room is not dominating the response? Or the content? I have done a video on this very topic: "Reviewing Speakers - Measurements and Listening Tests"
https://youtu.be/_2cu7GGQZ1A
In there I show published studies involving professional audio reviewers and how unreliably and poorly done their assessments are. If they can't produce reliable evidence for speakers, what hope is there for amps, DACs, etc.? Answer is none.
So once again, measurements are your friend, not your enemy. Don't try to convince yourself otherwise with an argument like that.