I've been to Gold Saucer twice today, and I noticed both times that there is a grinding noise that starts SOMEWHERE in there, though I have not pinpointed the source, which persists through zone changes, duty instances, and even on the title screen. The sound goes away when I am on the PS4 main menu screen and returns when I switch back to the client. If I exit the client, the sound stops, but if I log out, the sound continues on the Title Screen.

The sound itself sounds like a fast ticking egg timer, or a constant low level grinding. Think like the timer from the board game Perfection.