Hmm, the black canary, though I have to admit I began disliking the series Arrow. This is a very good article on the application and the effect of ultrasound.
Do you know they're also used in sound tracks of horror movies to make you actually feel uncomfortable? Though I can't remember if it is Ultrasound of Infrasound.
RE: THE BLACK CANARY SCREAMS: Does It Really Exists, Even It Does Where Can We Find It In Real Life?