Blind testing is completely relevant to audio. But I would not use it to choose a component for purchase, as that is the wrong way to use DBT.

DBT is used to define differences without introducing prejudices that sighted testing can do. Like testing the differences between Dolby Digital and DTS, and interconnects against interconnects(or speaker wire). It can be used to test the audible differences between tube and SS amps, or a metal dome against a soft dome within the same speaker.

Listening to equipment for purchase is quite a different thing than listening for differences. One has to reach you emotionally, the other more critically without emotion.