Calisto Yew is an attorney in the fourth case. She is dismissive of Edgeworth and Franziska, and she laughs at both of them a lot because of the way they act. She doesn't take anything seriously. Her voice should switch from joking to playful pretty quickly. Her voice should be on the lower side. 

(Be good at laughing)

Spoiler: She is actually a master thief and the true culprit in this case. She is actually pretty smart and attempts to frame gumshoe for the murder.