Aw, shucks. That is nice of you to say. I've put a lot into my system and appreciate that you notice and appreciate that. Thanks man.
I suspect expectation bias, yes. I also think a lot of folks are insulted when I suggest that, but it's not an insult. It's a fact about the human brain and no one, no one can completely escape their biases. It's very strong, pervasive and a bane for good science. Your brain is fully capable of perceiving things that aren't there (or missing things that are there) and we can be very convincingly fooled. Especially when you're looking for, or primed to expect something. I wouldn't trust my own brain unless there were some controls.
It happens in science all the time. What, we've had incontrovertible scientific evidence of life on Mars, and more recently life on Venus! Both claims have since been examined more closely and alternate explanations have been put forth that could explain the observatons. When it was first announced tho, they were convinced. Bill Clinton announced the Mars thing as fact during his presidency! Good ol' peer review.
A lot of the scientific method and peer review are the attempt to eliminate biases. Scientists go to great pains to eliminate as much as possible to avoid false positives. That's where DBTs for listening comparisons come in. The few I've read about, once biases are removed under controlled, blind conditions the testers have never been able to consistently tell one from another. Not an easy thing to set up tho. There's a lot to account for.
