We now understand part of the reason why we can outperform test equipment as critical listeners; we are able to use the identical playback systems for both live and "recorded" music. The same ear/brain mechanism that we use to process what our ears pickup is used to process the memory of what we previously heard and then we can compare the two for accuracy. The same cannot be said for test equipment or even our home's playback systems.
This amazing ability we have of evaluation happens despite changes in noise levels or location. In other words, it isn't necessary for our playback of a recorded event to be identical in terms of background noise or even be in the same room for us to identify the sound as something we recognize. We routinely recognize and understand speech even in a crowded noisy room.
When you listen to an LP you're able to ignore the ticks, pops, distortions and surface noise of the record and make an evaluation of whether it seems live or canned in the studio. When you're in a crowded restaurant and hear live music playing, you know it's live despite the background noise.
Think of how great your music system would be if you used the exact reverse of equipment used to record the event in the first place.
Tomorrow we'll start on digital copying.