Ooh, this is fun lets continue adding to the list of possible sources of distortion.
10. Ceiling vibrations. (Weve got walls, floors and windows dialed in, but lets not forget the ceiling. And furniture. And glassware. And clothing. And hair gosh how could we forget hair. Wee little hairs is how we hear anyway, and just imagine using the wrong shampoo. Totally f-ed.)
11. Ectoplasm. Gostbusters, anyone? Nuff said.
12. Matter. Dark matter is particularly insidious (it can really sneak up on you, you rarely see it coming), but all of it can be problematic / fatiguing. More so with the stuff we know exists.
13. Electrons. Yes, they may be everywhere, but they can really tire you out. And if you run them through conductive materials just so across energy differentials, they can also be quite useful when mixed appropriately with electronic devices.
14. Tachyons. Invisible, immeasurable, theoretical, sound exhausting.
15. Weather. High pressure, low pressure, changing pressure, static pressure, too dry, too humid, too cold, too warm. Again, f-ed, f-ed and f-ed.
16. Residue(s). Of all manner, really. Psychic can be particularly bad. Psycho-acoustic residue can accrete and be notably fatiguing. High-viscosity petrochemical residues are best avoided definitely do not treat your listening environment with these types of sprays, particularly the flammable kind (i.e., napalm may look like fun in the movies, but its really not safe for home use, or anything else). Emotional residue. Be nice.
17. Sound waves. The root of all evil. And the vibrations that cause them (see also, vibrations, bad compare good vibrations). Enervating.
18. Atmosphere(ics). See also, weather and sound waves. The ineffable majesty of fluid dynamics aside, no atmosphere, no exhausting noise. At all. Problem licked. (And the tree-falling-in-forest conundrum is pure bonus points, as no one around to hear in any event.)
19. Perceptual lense(s). Subjective-based, epistemological reality is really the pits. And soooo exhausting.
20. Parallel universes. And no, not higher order dimensions, those sound divine. Parallel four-space, alternate space-time continuums. You do not want these rubbing up against your listening environment, the possibility they may be infinite and effectively omnipresent notwithstanding. Im sure theres a spray for that (but see, residues).
21. Magnets. And magnetic fields. Even the ones that make your speakers go. And the ones created by No. 13, above. But mostly the earths magnetic field, totally fatiguing. And: magnets, how do they work, anyway?
22. Plants. If you have to ask, youll never get understand. But trust me. Plants.
23. Water. Things sound crap under water, yet were mostly made out of water. Think about it.