"What is the happiest sound in the world? The roar of coins pouring into a metal tray when you hit a jackpot playing slots? The final school bell of the year, signaling the start of summer? The cheer of the crowd when your team wins a match?
Sure, all those things are great, but I think the happiest sound is one heard over 4 million times a day, all over the world: the notification beep that your Xbox makes when you earn an achievement. (Yes, it’s the same sound you hear when getting a friend request or a game invitation, but those things just make the sound even happier.)
Did you know that the “Achievement unlocked” toast and the happy sound that goes with it were a last minute addition before we released the Xbox 360?"