I have several crystals in my office. Mostly hippie-type stuff. Citrine, quartz, tourmaline, amethyst, etc. etc. I can detect no effect on sound, positive or negative.
Some of them are pretty, so, I guess, if they help put me in any better mood or state of mind, then they probably positively affect the perception in some minor subconscious manner.
Some of them are pretty, so, I guess, if they help put me in any better mood or state of mind, then they probably positively affect the perception in some minor subconscious manner.

