Minae Matsukawa, Ace Attorney series producer, has started a developer blog on the official Ace Attorney website. In the first entry, she discusses the early planning of the U.S. version (and therefore the DS port in general) of the first game, Phoenix Wright: Ace Attorney. According to Matsukawa, the idea to yell into the microphone came from American Capcom staffers who thought it was an obvious must-have. "'So, do we get to do some yelling?' an American staff member asked me. 'E-excuse me?'"
The Japanese staff weren't keen on the idea of adding a bunch of unnecessary features, but creator/writer Shu Takumi recognized the importance of making the American audience happy. The rest, as they say, is an optional feature in a video game.
Speaking of American Ace Attorney staff, the post mentions an interesting bit of trivia that we've been looking for an excuse to share. Ben Judd, who was part of the localization team, provided the American voice of Phoenix Wright. He's now the producer on the new Bionic Commando games.