I have a phase inversion switch on my DAC, which can be controlled with the remote. I can hear a difference every time I switch polarity on any CD, but many times I cannot truly tell which is "correct". Yes, I can hear polarity, and I believe it is important. The author who cites the Wood Effect brings out many good points. The main item is the lack of a standard, i.e. the compression part of the original air motion should be reproduced as a compression wave from the speaker. Another interesting point is mixing. What if mixed-in music, maybe recorded at a different studio or with a different engineer, is not the same polarity as other parts of the recording? What about phase preservation when FM radio reception is demodulated? Another concern is that original polarity is not preserved over the entire frequency spectrum in both the recording and during playback. Maybe this is why analog playback is still popular and preferred by many audiophiles. There is no digital signal processing, the grooves in the LP are at least a close approximation to the original air motion.