"Beep, beep" or beep-beep is onomatopoeia representing a noise, generally of a pair of identical tones following one after the other, often generated by a machine or device such as a car horn. It is commonly associated with the Road Runner in the Looney Tunes cartoons featuring the speedy-yet-flightless bird and his constant pursuer, Wile E. Coyote. "Beep, Beep" is the name of a 1952 Warner Brothers cartoon in the Merrie Melodies series.
Chuck Jones, the creator of the Road Runner, has stated that this sound, the only way the Road Runner can harm the Coyote, was inspired by hearing a Doppler-like effect as background artist Paul Julian carrying set backgrounds beep-beeped when he could not see where he was going. Although commonly quoted as "meep meep", Warner Brothers, the current owner of all trademarks relating to the duo, lists "beep, beep" as the Road Runner's sound.
The "beep, beep" sound was the theme in a tempo-changing novelty record. The "Beep, Beep" (the Little Nash Rambler) song was recorded by The Playmates in 1958. The record became a #4 hit on the Billboard Top 40 chart for twelve weeks. The lyrics have the beep-beep horn of the compact car humiliating the driver of a Cadillac going ever faster as the Rambler driver keeps up to find out how he can get his car out of second gear.
In 1978, Warner Brothers recycled the Road Runner's "beep, beep" sound for its TV series, Wonder Woman, which featured a tiny robot-on-wheels named Rover who makes the "beep, beep" sound on occasion.
So popular was the image of road-burning speed inspired by the Road-Runner, that Plymouth (a division of Chrysler Car Company) named one of their V8-powered "Muscle Car" models after the Road-Runner, and the car was fitted with decals of the road-runner and a warning-horn that made the well-known "beep, beep" sound when activated.
In comic books, the Road Runner's actual name was "Beep Beep".