I’ll post a few links below as examples, but I’m just curious as to whether or not these beats work. A few claim to help with sleeping, anxiety, and some say they boost serotonin. Are they legit or is it just said to make you think they work (psychosomatic)

I do feel relaxed and slightly sleepy when I listen to them. Could be just me though. Also, if anyone has any good apps suggestions that play calming noises while you sleep with a timer that would be nice :)
Examples:
Happiness Frequency – Serotonin, Dopamine and Endorphin Release Music

deep sleep immediately with delta brainwaves music

432 Hz