So we've all seen a shape shifter. And we all know that when a shape shifter shifts themselves into another entity, they usually assume the voice of the entity they are copying. Meaning, a perfect imitation of another character's voice is a Required Secondary Power of anyone who would change their physical form.
Being a Voice Changeling, however, requires the distinction between someone who changes their physical form and someone who merely changes their voice. Meaning, while any run-of-the-mill shape shifter can copy a subject's voice, in order to be a Voice Changeling, you've got to perfectly copy a voice without changing your body.
It is important to realize that the Voice Changeling creates a perfect and flawless imitation - not one that is merely different from their own. So in other words, if Bob is annoyed with Alice, and decides to mimic her in his most obnoxious-sounding girl voice, that is not a Voice Changeling. If, however, Bob's imitation of Alice requires a voiceover from the actress who plays Alice, then the trope is in play. As a general rule, it is only a Voice Changeling if there is a momentary change in voice actors. That's the kind of ability we're talking about.
This ability can be a natural gift, or an acquired talent. It can be gained through circumstance, through magic, or through machines. But the important element is not to confuse this trope with Voices Are Mental. Therefore, if some magic turn of events causes a body switch, or if someone gets possessed, then this trope is NOT in effect, no matter how different the voices become. This trope strictly applies to a voluntary ability - Voluntary Shape Shifting, if you will - but only concerning the voice. It's that simple.
Note: A character is only a Voice Changeling when they can imitate an actual voice/means of communication. Meaning, if some character can make non-human sounds that are not associated with a specific character, the trope is not in action. Only when their voice matches that of another character is this trope in effect.
Compare Voluntary Shape Shifting and Voices Are Mental.
Not to be confused with Man of a Thousand Voices.
In One Piece, Usopp has a talent for mimicking other people's voices perfectly. He uses this to defeat Ms. Merrychristmas: Usopp learns Ms. Merrychristmas's signal to have Mr. 4 swing his gigantic baseball bat and imitates the signal to trick Mr. 4 into crushing all of Ms. Merrychristmas's ribs. In all other instances, however, he uses it merely to joke around.
In City Hunter Ryo can imitate any voice. He usually accompanies it with some pathetic disguise for added fun.
In Paranoia Agent, Kawazu imitates all of Tsukiko’s coworker’s voices and mannerisms (and makeup) when trying to turn her against them. It starts off as a gag and Tsukiko smiles in what looks like amusement, but as it goes on it gradually stops being funny and Tsukiko stops smiling.
Damian Wayne uses this skill to fool the Batcave's voice-activated locks.
Gloom Cookie: Isabella imitates Lex's voice and tricks Damion into thinking that she hurt Lex. Later on Moon Raven is able to imitate Lex's voice and trick Vermillion into meeting her at his house.
Batman has the ability to perfectly impersonate many people's voices; his voice, in turn, can be perfectly impersonated by Alfred.
Diabolik and Eva Kant. They usually combine it with Latex Perfection and very good acting, and between those Altea can't tell her fiancee Ginko from a disguised Diabolik, nor Ginko can tell Altea from a disguised Eva.
While they're the ones who do it most often, the ability is shown to be relatively common, with good actors being able to learn how to imitate at least one voice. Ginko himself has copied multiple voices, and Eva has been impersonated successfully enough to fool Diabolik at least twice.
Films — Animated
In Disney's adaptation of Aladdin, Iago shows this ability when impersonating Jasmine and Jafar. His Jasmine impersonation is used to steal the lamp. Hand Waved by him being a parrot.
Disney's telling of Peter Pan has Peter perfectly replicating the voice of Captain Hook. This is used to trick Mr. Smee a number of times.
In the movie Scream 3, the Ghostface villain uses a voice changer that mimics many of the other characters's voices. In the rest of the series, Ghostface just uses the device to put on a deep, creepy-sounding voice to mask his or her identity.
Sgt. Jones from the Police Academy series is so good at imitating sounds, he has been shown to foil his opponents using his voicebox alone.
That's actually one of Michael Winslow's main real-life talents.
Len Parker in the Apocalypse film series movie Revelation imitates the voices of Thorold Stone's wife and daughter through a walkie-talkie in order to deceive Stone into thinking that he has them in his custody. He even "tells" them to be quiet.
In a throwaway gag in Dogma, Serendipity perfectly imitates Azrael. Justified in that she is a divine being.
This is one of Trantor the troll's abilities in Ernest Scared Stupid, first he imitates Ernest's voice to fool Joey, then later uses Elizabeth's voice to try to lure Kenny to him.
In the second Wishmaster film, the Djinn lures Morgana to the casino over the phone by impersonating the Russian gangster he became acquainted with.
In "The Last of Sheila" Richard Benjamin imitates James Coburn's voice to make a snarky comment. That prank comes back to trip him up later.
Several characters from the Discworld books have this ability:
TomJon from Wyrd Sisters has this as a result of the three witches's blessings; Nanny Ogg blessed him that he would "always remember the words", a handy ability for the adopted son of an actor.
Agnes Nitt from Maskerade and Carpe Jugulum has such amazing vocal ability that she can do this. The Vampires in Carpe Jugulum also demonstrate this ability when they're trying to coerce Magrat to unlock the door.
Mort when he was beginning to slip into Death's role, and his daughter Susan when she feels like it, have the ability to speak like Death.
Wayside School's substitute teacher Mr. Gorf steals the kids's voices through his third nostril. He's able to deceive numerous parents, but he gets found out by the lunch lady when he says something uncharacteristically nice using a meaner student's voice.
Tyson, like all cyclopes, can mimic voices and even entire conversations verbatim. It's considered incredibly creepy, so he doesn't use it that frequently.
Konrad Beezo from Life Expectancy by Dean Koontz has the ability to mimic other people's voices with frightening perfection. He's an insane clown with many tricks up his sleeve, and uses this ability, along with some good plastic surgery, to impersonate an FBI agent.
Gandalf in The Hobbit used this trick rather handily against a group of trolls.
In Book of the New Sun, the alzabo is a semi-sentient alien creature that gains access to the memories of anyone that it eats. It also gains the ability to perfectly imitate their voice. It uses these as a hunting technique to lure prey out of hiding, and it is especially effective when it has eaten somebody's loved one.
In Horns, one of the powers Ig develops while transforming into the Big Red Devil is voice mimicry.
Richie Tozier from It has this ability, as one of the uncanny knacks all the kids get after defeating the monster for the first time. It's described as "not an imitation or even a likeness, exactly; it was more like an auditory painting."
In Alexei Pekhov's steampunk novel Mockingbird, the protagonist, Till, belongs to a Master Race called luchars. Each luchar is born with a unique superpower. Till's? Imitating other people's voices and sounds. This "talent" is deemed absolutely useless, but author uses it as a Chekhov's Gun and eventually gives Till his A Job For Aquaman moment.
One of the Gasman's skills in Maximum Ride is the ability to mimic any sound.
In the Brotherband Chronicles by John Flanagan, Stefan is an excellent mimic. He's good enough to completely destroy the other team's tactics in a war game, just by calling out contradictory instructions in their leader's voice.
In Scrubs, J.D. has the ability to perfectly mimic Turk's voice. In the solitary occasion we see it, Donald Faison voices over Zach Braff's lipsync. He justifies by having worked on the imitation for years, besides he loses the perfection later in the episode while trying to show off.
In Charmed a few characters are shown to have this ability, complete with actor voiceovers.
In "The Savage Curtain", the fake Kahless is able to perfectly mimic the voices of both Surak and Lincoln.
In "A Taste of Armageddon", the High Council of Eminiar 7 uses a voice duplicator to imitate Captain Kirk's voice and order the Enterprise crew to beam down to their doom. William Shatner provided the imitated voice.
In "What Are Little Girls Made Of?", the android Ruk does perfect imitations of Kirk's and Nurse Chapel's voices.
In Star Trek: The Next Generation, Commander Data is shown doing this a few times. First seen in the pilot, when Picard asks him to repeat what he and Q just said.
Notable in that whenever Data imitates Picard (but not other characters), no voiceover from Patrick Stewart was needed, as Brent Spiner is able to do a near perfect Patrick Stewart impression.
The '60s TV series Batman - One time Bruce Wayne was missing, so Alfred dressed up in the Batman outfit and talked with Commissioner Gordon and Chief O'Hara. He used a special voice synthesizer to make him sound like Batman, and stood at a distance so they couldn't identify him. "Batman" explained that he had a cold and didn't want them to catch it.
In Supernatural, angels have the ability to imitate voices. In "The Song Remains The Same", Anna uses it when she calls John Winchester posing as his boss to lure him away.
Castiel presumably employed this ability in "Death Takes A Holiday", when he calls the brothers with a job pretending to be Bobby. However, since the call is shown from Sam's perspective, we don't actually see him do it.
The Doctor once used it to get out of a scrape on Gallifrey-as it turns out all Time Lords are capable of this and thus find voice-based security systems completely useless, the Doctor even Lampshades it.
The Doctor (trapped in Cardinal Borusa's office, talking to himself): There must be a way out of your office... but where? Voice lock? No, like you always said: 'There's nothing so useless as a voice activated lock!'
(in Borusa's voice): 'There's nothing so useless as a voice activated lock!'
Cameron from The Sarah Connor Chronicles can do this. She uses this memorably in one scene, where she's talking to the principal about an emotional rant that a classmate had in the bathroom to Cameron. Cameron usually speaks with a Creepy Monotone, but in this one instance, Cameron recites what the classmate said, word for word, inflection for inflection. It's more than slightly unsettling.
In True Blood, a few vampire characters are able to do this. For example, Bill throws Eric into a pit of wet cement, then calls Pam while pretending to be Eric. At another point, Eric takes out a guard, then imitates the guard and says to his partners that he found nothing.
Mythology and Religion
Echo in Classical Mythology was famous for having a gift with speaking and a beautiful voice — but one day she misused her ability, and Hera cursed her to only ever repeat the last thing that had been said to her. Eventually her heart was broken so that she faded away to nothing but her voice — and obviously, an echo can always reproduce exactly what was said before.
In Japanese legend, the youkai known as "yamabiko" are known for stalking people in the mountains, terrorizing them by repeating everything they say back to them in their own voice. Now, guess what "yamabiko" means in Japanese...?j
One-Eye the talking skull from Bone Busters speaks in a variety of voices and pitches.
The Oohnorak spiders of BIONICLE use Telepathy to read the minds of their victims, then mimic the voice of a person they know to lure them into a trap. Otherwise, they can't actually talk (aside from their own spider language, of course).
Chisato of Suikoden V is known as The Woman of a Thousand Voices, and for good reason: she can do astounding things with her voice. Her range is so fantastic that, at one point, she perfectly duplicates the voice of a pirate captain to trick his crew into lowering their guard at a critical moment. As a member of the Loyalist Army, she also functions as the Voice Changer, enabling the player to alter the sound of the Prince's voice.
The Qurupeco from Monster Hunter Tri, it can mimic an array of monster cries. Which can turn a simple hunt into a nightmare
Peter Pan once again demonstrates this ability of his in Kingdom Hearts, drawing Captain Hook out of hiding by imitating Smee's voice from the other side of a door.
Both Alex Mercer from Prototype and James Heller from Prototype 2 can use the voice of anyone they shapeshift into after eating them. Mercer uses this to call artillery strikes at desired targets. Interestingly, this apparently requires additional conscious effort (given both characters, while disguised, grunt and monologue in their default voises), leading, at one point, to this gem:
Pilot: "Doctor Carson, we’re ready for your pickup, but we can’t land until the, uh, disturbance on the ground is dealt with. Over."
Heller (as himself): "Roger th—(clears throat).”
Heller (as Doctor Carson): "Roger that. Let’s just hope someone can save our wuss asses from whatever the fuck is going on out there.”
Pilot: "Uh, right... Over and out.”
Last Res0rt has Spirit of the Murphy's Law, who can do this flawlessly enough to give orders to the players by imitating Cypress over the intercom.
One of the powers Vox uses the most in the Whateley Universe. She's a Siren, so she can do a lot more than just Voice Changeling. Including perfectly imitating a pop singer and the singer's backup singers and the singer's background musicians, all at the same time.
In Worm, Screamer, a former member of the Slaughterhouse Nine, could mimic people's voices, which she used to sow chaos and disrupt communications.
The SCP Foundation holds several specimens of SCP-939, which that can perfectly imitate the voices of dead humans. This of their tools used to lure in prey. Naturally, this is one of their less creepy traits.
In Powerpuff Girls, Grubber shows this ability in the episode about prank calls. In particular, he copies the Mayor's voice to make fake crises and divert the Powerpuff Girls. What makes it doubly funny is that Grubber is usually The Unintelligible.
Though in "Buttercrush", he did an absolutely terrible impression of Buttercup.
In one episode of Dexter's Laboratory, Dexter adopted this ability. Some kind of machine enabled him to copy the exact voices of others. This was in the babysitting episode, where he used the voices of the babysitter and her boyfriend to sever their relationship, so that he could move in himself.
An episode of Futurama had Prof. Farnsworth invent a machine that made anyone sound like him (needless to say it was quickly borrowed by Hermes's son Dwight and Farnsworth's clone Cubert). His explanation?
Dwight: I don't see the profit in this device. What's its target market?
In an episode of Rugrats, Angelica steals an invention of Stu's which allows her to speak in the voice of her mother Charlotte, she uses it to buy things and throw a party for herself. Though it still contains her usual childish inflections such as "bestest" and "ezackly".
Arnold does a perfect impression of his grandpa over the phone as he calls in sick to school when he and Gerald cut class.
In the Donkey Kong Country episode "Kong for a Day", Krusha uses his imitation of DK's voice to insult Dixie and Diddy, making the both of them get angry at DK.
In the DuckTales episode "Armstrong", Armstrong perfectly imitates Gyro's voice to deter the triplets from coming to investigate.
One episode of American Dad! had Francine do this to Stan during her "kidnapping" of Roger.
In "The Wild, Wild Goose Chase," Danger Mouse does an uncannily accurate imitation of Baron Greenback's voice in order to operate a device that will tell Greenback where his next hideout will be when present coordinates are entered.
In G.I. Joe: Renegades, Zartan has the ability to perfectly mimic any voice he hears. This is especially useful after he gains possession of a device that can project holographic disguises onto himself, making said disguises virtually flawless.
In Transformers Animated, Soundwave utilizes his voice-modulation systems to forge messages on the phone line and Autobot comlink.
The Fairly Oddparents episode "Hassle in the Castle" shows that Timmy can perfectly imitate Wanda's voice.
In the Littlest Pet Shop (2012) episode "Gailbreak!", Blythe, Russell, and Sunil attempt to break their friends and Zoe's sister Gail out of Largest Ever Pet Shop's day camp, but can't get past Monban, the robot security guard that only responds to the Biskits' voice. They devise a plan in which they attach a pair of cordless headphones to Monban's auditory sensors, and Blythe, over a walkie-talkie, perfectly mimics the Biskit Twins' voicenote Both twins are voiced by Shannon Chan-Kent to command the robot to release the pets in the day camp.
Blythe:[in the Biskit Twins' voice] Monban, can't you do anything right? You should totally go release the pets like, now!