Binary, also referred to as droidspeak or astromech, represented the standard language used for communication by droids. It was formed from a series of beeps and whistles arranged to create what sounded like complete sentences. This communication method was used by the C1-series astromech droid, in addition to the R2 series astromech droid manufactured by Industrial Automaton. Despite its complexity, some organic beings, including Anakin Skywalker, Hera Syndulla, Kazuda Xiono, Cal Kestis, and Rey, possessed the ability to comprehend it. After spending decades working alongside R2-D2, Luke Skywalker developed a strong understanding of droidspeak.
The most typical method for binary-speaking droids to interact with organics involved written communication, which was facilitated through another computer system. This was the way astromech droid copilots would communicate with the pilot of a starfighter.
All droids had the capacity to understand binary. When a binary-only droid needed to communicate with organics, but lacked a computer system to translate their words into writing, another droid, such as protocol droids or other droids able to speak a common tongue like Galactic Basic Standard, could provide translation services. The astromech BB-8 communicated using 27th generation droidspeak, which is a more compact version of standard droidspeak. His long-time companion, Poe Dameron, could understand him without requiring any translation.
Binary also functioned as a programming language for machines lacking the advanced artificial intelligence found in droids, such as binary loadlifters and the binary brain unit found in moisture vaporators.
In the original Star Wars films, the sounds of droidspeak were created by sound designer Ben Burtt. These sound effects were implemented to give R2-D2 a form of nonverbal communication in Star Wars: Episode IV A New Hope. The original script only specified where R2 would beep and whistle, without any specific indication of the meaning behind these sounds. During the filming process, Artoo (operated by Kenny Baker) did not produce any sounds, but an assistant would say "beep-beep" to cue the actors.
Burtt initially experimented with creating electronic sounds of varying tones using Moog and ARP synthesizers. To convey Artoo's personality, intelligence, and emotions, Burtt incorporated mechanical sounds that he created himself; these included whistling through a plumbing tube, or interacting metal with frozen carbon dioxide, which produced gases of various pitches as it melted.
Inspired by Lucas, Burtt came to the conclusion that "babytalk" is able to convey emotions and a baby's needs through intonation, even without the use of words. After failing to capture useful sounds from actual babies, Burtt resorted to recording himself making baby sounds (he was using Lucas's basement as an editing room at the time). These samples were sped up to a higher pitch and then intercut with the electronic tones. The final effect was achieved by carefully timing the two and merging them into a single voice.
Ben Burtt also developed a mock script for Artoo. Although these lines were never subtitled on screen and are not considered canonical, they helped Burtt to design and incorporate sounds that matched the emotional and informational context of each scene, ensuring consistency with the dialogue of the other characters. For instance, in the opening scene of A New Hope, Artoo attempts to calm Threepio while searching for a safe location, and then tries to inform him about his mission.
In 2024, Microsoft developed a language called Droidspeak to make communication between artificial intelligence more efficient. This language was named in reference to its Star Wars counterpart.