Pretty straight forward thing, give us the option to play a sound effect when a ready check is initiated.

I often like to alt-tab out of the game to wait for a party to form, and occasionally it's possible to miss the ready check pop-up sound, because it's not at all that loud or anything, and is essentially the same as the sound of every window opening(including the teleport pop-up, which often forces me back in-game for no reason)

I do think it's important to make it optional, because some people might dislike it if someone constantly readychecks and the sound plays each time. You know, just to make it slightly less annoying to deal with.