I did that, too. Here are the two files in Audacity:
Now we invert d.wav:
And, finally, we choose Tracks→Mix→Mix and Render:
Dead silence. The two tracks are identical. Any difference David is hearing is entirely in his head.
But could we even have expected anything different? Of course not. Ripping a CD to WAV is simply transcribing the PCM data from pits on a silvered disk to bits on your hard drive. It’s either done correctly (same bits in both media) or it’s done incorrectly.
If it’s done correctly, then the bits transcribed are identical to the bits on the CD. There’s no “room” for improvement.