Vertex Group LLC (plaintiff) applied to register a sound as a trademark. The sound was a quick, “descending frequency sound pulse,” beeping four to five times per second. The application stated that the sound’s noises were between 1500 hertz (Hz) and 2300 Hz. Vertex used the sound in connection with a personal security alarm for children. Vertex had a utility patent for the alarm but not specifically for the sound. Vertex’s advertising focused on the alarm’s noise. The trademark examiner rejected the application on the ground that the sound was functional. Vertex appealed.