The device was first mentioned in "The Luminous Fish Effect" by Mary Cooper while she was telling a story about Sheldon's childhood. Sheldon was devastated when the government inhibited his nuclear reactor work. Then he built a "sonic death ray" which did not slow down the neighbor kids, but pissed of their dog. In "The Ornithophobia Diffusion", the Ultra Sonic Blaster is a high-frequency tone generator Sheldon uses on the Black-throated Magpie-Jay (later known as Lovey-Dovey) on his window sill in an attempt to scare it away.