Originally Posted by TheOtus
2nd is obvious, but first? If you´re tired and unfocused, how are you suppose to hear better and more detailed??
It's a curious thing and seems counter-intuitive but it is in fact what I've found IME. Just to clarify, I don't think being tired makes you focus on more details, rather it lets you immerse yourself more fully and more easily in the music. I'm not sure why, but when I'm a bit tired I enjoy the music much more. Ofcourse, being tired could mean several things, such as being physically fatigued, bored etc. but I specifically mean "sleepy" in my case. I'm also not saying that it requires an extreme of such a state, like being completely exhausted or mentally drained; just a slight drowsiness is sufficient.
I actually think focusing too much on a particular aspect of the music is detrimental to its enjoyment. It's much better when taken in as a whole, and this is what being tired accomplishes for me. I've always felt this, but really started getting interested in this phenomenon in the past year when I changed my schedule to accommodate more night-time listening.
Originally Posted by Bullseye
As we are animals in the biological sense we keep looking for self preservation of our species and ourselves as individuals. For that reason when night comes there is less visibility and "danger" is always present, but can't be seen as easy as when there is light. Consequently our senses may work in a more thorough way. For that reason our pupils dilate and our brain might give more attention to sounds. I am sorry if I have not expressed it correctly, in the way I thought about it, but I am tired and my english doesn't come out as easy as I'd like it to. Basically when night comes we have to become more aware of our surroundings (eyes and ears, as our eyes can't see as good as when there is light). On the other hand, the reason might be what koyaan said.
This is an excellent point. We've evolved to do many things to help propagate our species (mostly in ancestral times). It's not unlikely that the tendency to have keener senses at night was selected for over time to detect threats such as predation. This would also help explain why listening to music with the lights turned off is more pleasurable for many (including me).
Edit: I realize that chinesewiki already made this last point in post #20. I also saw Uncle Erik's post and strongly agree with his observations as well. The psychological aspects he described make sense. As for physiology, we go through cycles of hormonal change throughout the day that affect sensations, perceptions, thoughts etc. Circadian rhythms are a well-known example, which determine sleep patterns according to the amount of sunlight. All this only strengthens my belief that the effect of better SQ at night is primarily physiological/psychological in nature.