The computer voice was an audio interface program designed to allow computers to express information verbally. Many space-faring cultures, such as the United Federation of Planets, the Romulan Star Empire and the Cardassian Union, equipped their computers with this feature.
Over 200,000 years ago, the Iconians equipped a facility launching Iconian probes on Iconia with a female computer voice. (TNG: "Contagion")
Starfleet starships utilized computer voices by 2256, a feature which continued to be used throughout the 23rd and 24th centuries. (DIS: "The Vulcan Hello"; TNG: "Encounter at Farpoint")
The computer voice of the USS Enterprise was reprogrammed in 2267 on Cygnet XIV, with the intent of giving it a less mechanized personality. The resulting modifications caused the computer to address James T. Kirk in an increasingly amorous manner, as well as giggle. This modification was short-lived. (TOS: "Tomorrow is Yesterday")
While most Starfleet computers utilized female voices, the M-5 multitronic unit in 2268 had a male voice. (TOS: "The Ultimate Computer")
In the alternate reality, the USS Vengeance had a male computer voice. (Star Trek Into Darkness)
In the mirror universe, the ISS Enterprise (NCC-1701) had a male computer voice. (TOS: "Mirror, Mirror")
After Bynar modifications to the USS Enterprise-D in 2364, the starship's computer for a short time used both the usual female and a male voice. (TNG: "11001001")
Starfleet environmental suits were also equipped with a computer voice. (Star Trek: First Contact; VOY: "Day of Honor")
In the 32nd century, a starship owned by Cleveland Booker had a male computer voice. (DIS: "That Hope Is You, Part 1")
Background information
The original computer voice
The computer voice on most Federation starship and fixed installation computers was portrayed by Majel Barrett-Roddenberry since the early days of Star Trek: The Original Series (first appearing in "Mudd's Women"). The computer voice in TOS and Star Trek: The Animated Series was very rhythmic and mechanical.
Following TOS, Majel Barrett-Roddenberry continued to play Starfleet computers; however, it became a far more normal-sounding female voice. She continued the role on Star Trek: The Next Generation (with the exception of some early episodes), Star Trek: Deep Space Nine, Star Trek: Voyager, and Star Trek: Enterprise. There is only a single word spoken by a computer voice in the entire run of ENT, which is when Majel Barrett's computer voice of the USS Defiant twice states, "Working…" in the episode "In a Mirror, Darkly, Part II".
She further provided the computer voice in all of the TNG films, through the alternate reality reboot film Star Trek. This 2009 contribution was her final performance both as the computer voice and in a Star Trek project before her death. Archived audio was also used in PIC Season 3.
