The color swatch analogy breaks down because it's easy to see two things side by side but it's impossible to hear two thing side by side. You can only hear two things at once. The sound morphing idea might be good improvement to the standard fast switch ABX test though. The other thing you seem to be missing is the specific context in which ABX tests are usually talked about on here. It's to determine if a difference which someone already claims to hear is real or not. It's not just giving a random person 2 samples and asking them to discriminate between them with no other background about what they should be listening for. I wouldn't expect that to go too well either. The context in these circles is something like this. Audiophile A listens to both $5000 MegaAmp X and $200 CheapoAmp Y sighted. He declares MegaAmp X to be "obviously" superior with "night and day" differences even though they measure identically down to -80, -90, -100db or something similar. Skeptic B arranges an ABX test in which Audiophile A fails to distinguish the "obvious" differences which he previously "heard" when listening sighted. Audiophile A blames switchboxes for making everything sound the same and Skeptic B concludes that no difference between MegaAmp X and CheapoAmp Y have been demonstrated. Is there something wrong with using ABX testing in this way?