Sometimes, a dying character's voice undergoes some kind of change not in the mundane sense, by sounding a bit hoarser or a bit more clogged with blood than usual, but actually transforming in mid-demise.
Maybe it's because the character's an A.I. suffering from some kind of Electronic Speech Impediment as they finally break down; maybe it's because they're a shapeshifter and returning to their true form at the moment of death; or maybe they're having some kind of fatal transformation forced on them a character who undergoes Death by Deaging will sound progressively younger, for example.
Whatever the case, their voice changes as they slowly expire. May involve Dying as Yourself in some cases.
Needless to say, this is a Death Trope. Expect unmarked spoilers ahead.
- Big Finish Doctor Who:
- In The Holy Terror, the prison dimension finally ceases to exist when Eugene Tacitus commits suicide with the Child's assistance. With the prisoner dead, the Child's purpose is complete and thus slowly ceases to exist as well; as he does so, his voice audibly ages into that of Eugene himself before fading away entirely. For good measure, both Eugene and the Child are voiced by the same actor, albeit digitally altered to sound more childlke in the latter case.
- After getting blasted by the delusional Central Committee in Spare Parts, Cyberman Commander Zheng's distinctive sing-song speech grows slower and more ponderous as he breaks down — apparently dying after helping the Doctor save Mondas from the Committee. However, this is later subverted when Zheng turns up alive at the end, ready to begin the Cyberman project once again.
- Another Cyberman example crops up in The Harvest. Here, a Cyber-Leader known as Subject One has been partially converted into a human being at his own request, and as a result, his voice is almost completely human for most of the story. However, as he begins to suffer organ rejection, Subject One's voice becomes more metallic; when he can no longer force the Doctor to perform surgery, he's quickly reduced to hysterically begging for help in an electronically-distorted voice — before ultimately flatlining.
- During the climax of Singularity, having lost her grip on her human host, Great Quel is about to be flushed back to the end of time with all the other Somnus cult leaders. However, said host realizes that Quel cannot be allowed to escape or else she'll just start the plot all over again. So she traps the possessing mind inside her own body so that they'll die together when the tower explodes; as a result, the two of them spend their last few minutes fluctuating wildly between two different voices — one speaking in Quel's Received Pronunciation, the other speaking with her host's Russian accent.
- In yet another Cyberman example, Legend of the Cybermen features a Cyber-Planner attempting to take over the Land Of Fiction; however, thanks to the efforts of The Doctor, Captain Nemo and Count Dracula, it's ultimately hacked with a cybermat and forced to use the power it's usurped to edit itself and the Cybermen out of existence. As a result, the Cyber-Planner's normally-low voice turns high-pitched and shrieking as it declares that Cybermen do not exist, before vanishing in a Puff of Logic.
- In I, Davros: Corruption, the title character's mother ends up getting fatally mutated by deliberately exposing herself and an enemy spy to one of Davros' machines. By the time Lady Calcula is found, she's dying and her voice has degenerated into a warped, Voice of the Legion-style drone complete with Vader Breath.
- The Gemini Saint in Saint Seiya has two personalities in one body. After he is struck by Athena's staff during their first (and last) confrontation, his 'good' half briefly emerges and asks the goddess to forgive the 'evil' half. In the anime, this is marked by a change in hair color and voice. In the Italian dub, the voice actor of the 'good' half is female.
- Roboppi in Yu-Gi-Oh! VRAINS gained sentience and free will after being affected by Ai's backup program. While he was fine at first, it later became clear that the program became too much for him since he was originally made for household work. As a result he broke down during his duel against Soulburner and his voice started shifting till he regressed to his original voice and form until Soulburner gave him a Mercy Kill.
- In The Land of What Might-Have-Been, the monster known as the Hellion speaks in a Shifting Voice of Madness rendered in a jumbled patchwork of bold, italic, underlined and all-caps text. When Dorothy manages to fatally wound her, however, the the shifting factor begins fading away as the Hellion slowly succumbs to her injuries, leaving her with an ordinary human voice in her final moments.
- Early on in Light and Dark The Adventures of Dark Yagami, we see L use a Death Note on Light's Mom for the purposes of controlling her to send a threatening message to Dark. Once the Death Note takes effect and makes her give Dark the message, the narration tells us that she said it in a strange voice that wasnt hers.
- In Hellsing Ultimate Abridged, The Major's voice takes on a distinct mechanical reverb after Seras blows him in half and it's revealed he's a cyborg, as if he's speaking through a radio transmission or speech program. When he's shot through the head he eerily sings "So Long, Farewell" from The Sound of Music, gradually sounding distorted like a machine losing battery power, before finally dying.
- As the Other World begins to break down in Coraline, the Other Mother's creations begin to break down as well; as such, when the eponymous heroine confronts the Other Bobinsky for the last time, his voice is decaying along with the rest of him. Originally as loud and hammy as the original Bobinsky, the duplicate's tones have since become quavering and faint; then, as he speaks his final lines, his voice goes full-blown Voice of the Legion... right before he loses the ability to maintain a solid form and dissolves into a swarm of rats.
- After getting his burlap skin stripped away in the finale of The Nightmare Before Christmas, Oogie-Boogie is revealed to be a colossal mass of insects, and without the cloth holding them in place, he begins to fall apart. As a result, as more and more bugs begin to fall off him, his usual baritone grows higher and rapidly dissolves into dozens of tiny voices as the swarm comes apart; since most of them end up in the death trap he was intending for Sally and Santa Claus, he's left with only one surviving bug to escape with, squeaking out his last words in a near-incomprehensible falsetto — right before Santa Claus squashes him flat.
- 2001: A Space Odyssey provides one of the most famous example of this trope, with HAL-9000's mostly human voice growing steadily lower and more ponderous as he is slowly lobotomized.
- In Alien, Ash's voice becomes quite distinctly synthetic after being decapitated and unveiled as an android. Played with, given that he doesn't actually "die" until Parker incinerates him with a flamethrower, but it's apparent that he's been damaged beyond repair and not likely to survive anyway.
- In the climax of Child's Play, as Chucky lays dying his last words are to recite his Good Guy Doll catchphrase, with his voice rising at the end from his natural adult-sounding one to the childlike voice of the doll.
Chucky: Hi, I'm Chucky, wanna plaaaaaaaaay...?
- Crops up in Constantine: after being shot in the head and having his face reduced to a clump of talking shards, Balthazar's otherwise-human voice becomes a haunting, ethereal whisper — up until Gabriel destroys him, causing his last word to drop to a low, deep roar as he's disintegrated.
- In Day of the Dead (1985), one of Rhodes' men has his head pulled off, and his scream rises in pitch as his vocal cords stretch, before finally snapping. This is Truth in Television, by the way; the narrower your vocal cords, the higher your voice is.
- In Hellboy (2019), Gruagach ends up outliving his usefulness and is fatally shrunk back down by Nimue. Over the course of the next few seconds, his deep voice rises higher and higher, until a two-foot-tall Gruagach is left screaming his last-words in a childish falsetto. Then he pops like a blister.
- Having been speaking in an ordinary human voice for the last third of The Mummy (1999), after getting stabbed in the stomach by Rick, Imhotep reverts to his original deep, booming Voice of the Legion as he decomposes back into a mummy and sinks down into one of Hamunaptra's deep pools.
- Pointedly averted in Nutty Professor II: The Klumps: during his Death by Deaging, Buddy Love somehow retains an adult voice even after being regressed into a toddler and then into a puddle of rapidly-dissolving slime.
- Star Wars:
- In Return of the Jedi, the redeemed Darth Vader is mortally wounded by the Emperor and his life support system damaged beyond repair; so, in his final moments, he has Luke remove his mask so he can see him with "his own eyes." Without the the mask, Vader's voice goes from his usual electronically-enhanced Basso Profundo to Anakin Skywalker's natural speaking voice — an aged, dying whisper.
- In Attack of the Clones, the shapeshifting bounty hunter known as Zam Wesell is shot with a poisoned dart by Jango Fett in order to prevent her from spilling her secrets to Anakin and Obi-Wan. As she dies, she reverts to her normal form, her voice shifting and distorting to Voice of the Legion proportions as she does so. For good measure, she reverts to speaking Huttese as well.
- For most of Terminator 2: Judgment Day, the T-1000 has been speaking in perfectly legible English with Robert Patrick's distinctive voice. However, after being blown out of shape with a grenade launcher and tumbling into the molten steel below, it can only emit high-pitched metallic screeching sounds in lieu of speech; as a result, the T-1000's Shapeshifter Swan Song is spent screaming like fingernails on a blackboard as it slowly melts.
- In the finale of The Witches, the Grand High Witch is transformed into a mouse along with all the other witches at the banquet; with her voice having audibly changed along with her, she can only squeak incomprehensible orders... right before the hotel manager chops her in half. It's not known why this happened, given that Luke, Bruno and even other transformed witches have all been heard to speak in perfectly ordinary human voices as mice, but there you go.
- Makes an appearance in Animorphs #37: here, the Yeerk Inspector inhabits the body of a Garatron and thus talks as quickly as he moves, his dialog normally being rendered without spaces as a result. In the climax, however, Marco manages to bite him on the leg while in cobra morph; as the Inspector succumbs to the venom, his speech finally breaks up into single words, then grows steadily more halting until he cannot speak at all.
- The Dark Tower: Blaine the Mono, while suffering a fatal Logic Bomb after being beaten at the game of riddles by Eddie, is reduced to screaming his last words in the voice of an infant before reverting to an apparent Electronic Speech Impediment.
- In the Funfax INTER Active Secret Agent file Orbit Of Fear, sabotaging the robots' recharging station in advance will result in Mr Mogul's synthetic actors shutting down just before the deadly gameshow railroads you into an unwinnable fight. As a result, Cracky Dean's attempts to continue the show become slower and flatter as he breaks down, all rendered in loving detail in the cassette tape included with the book.
Well, that's a turn-up for the books! T-Rex... has... stopped. We'll. Be. Back. After. These. Messages...
- Doctor Who:
- "Ghost Light": The villain Light usually speaks in one of two vocal modes: a very high-pitched, almost effeminate tone of voice, or a deep, menacing snarl. However, when the Doctor springs a Breaking Speech on Light and convinces him that stopping change is impossible since Light himself has begun to change, the godlike bureaucrat commits suicide by dissipating himself whereupon his voice grows lower and hoarser until he's muttering his last few words in a halting, ethereal whisper.
- "The Parting of the Ways": Jack Harkness tries to slow the Dalek attack on Satellite 5 by deploying the Anne-Droid against them. To her credit, she manages to stop three of them with her transmat beam and a snappy recitation of "You are the weakest link!" But then another Dalek arrives and blasts her head off, leaving her voice to wind down to a digitally-distorted drone as she concludes "Goodbye..."
- "Sleep No More": 474 usually speaks in an artificially-deepened voice, as one of the indicators that she's actually a force-grown Grunt. However, after being fatally wounded, the deepening effect fades away, leaving 474 to speak her final words in an ordinary human voice.
- Played with in "DNA Mad Scientist": the mad geneticist NamTar normally speaks in a deep, refined voice. However, when Kornata injects him with a serum that reverses his genetic self-modifications, his voice gets higher and more primitive as he grows progressively less advanced, until he finally reverts to his original form — that of an unintelligent laboratory rodent. This doesn't physically kill the rodent, but it's made abundantly clear that NamTar's evolved personality is gone and isn't coming back.
- Also played with in any instance where it looks like Scorpius is going to kick the bucket: usually, he speaks in a calm, refined and rather high-pitched voice; when he gets angry — say, by being badly wounded — his voice drops several octaves as he reverts to his bestial Scarran half. For example, after his coolant system is sabotaged, Scorpius is last seen crawling for the only undamaged coolant rod in the area, furiously calling for help in a demonic snarl. However, on every single occasion, Scorpius somehow manages to survive due to "foresight and preparation".
- In the finale of The Haunting of Hill House, Steve ends up getting trapped inside the Red Room and pacified with an illusion of a happy life with Leigh — who is now pregnant. However, the moment Steve realizes that none of this is real, the Room turns the scenario into a nightmare: Leigh's belly begins to swell to horrific proportions as black mold eats her from the inside out; now speaking in the Voice of the Legion, she remarks that this will continue until she bursts open — though Nellie is fortunately able to awaken Steve from the nightmare before this happens.
- The Orville: After Isaac kills Kaylon Primary by ripping his head off, the latter continues functioning just long enough to curse Isaac, as his voice slows down and sounds more robotic.
- During the climax of The Outer Limits episode "Last Supper," the unscrupulous Dr. Sinclair is finally able to create his Fountain of Youth drug from the blood of the immortal test subject he's just recaptured. As such, he decides to give himself a dose... only to find out that he underestimated its potency by a very wide margin: over the course of the horrific-looking Death by Deaging that follows, Sinclair's agonized screams audibly regress to infancy along with him, growing steadily higher and younger until he's left as a baby lying helplessly on the floor. Then he dissolves into a puddle of unborn cells.
- Red Dwarf:
- In "Queeg", Holly is executed by deletion in a pretty clear shout-out to HAL-9000: in this case, while singing a farewell song, his voice drops lower and lower until he finally fades away... up until it turns out that the events of the episode were faked by Holly, including his "death".
- A similar instance of this trope occurs in "The Last Day", when Hudzen 10 suffers a metaphysical dichotomy as a result of being told that there's no such thing as Silicon Heaven: treating this as a full-blown Logic Bomb, Huzen's voice slows to a drone and trails off as he breaks down.
- In the Star Trek: The Next Generation episode "Descent," Data's brother Lore is finally deactivated for good, his voice slowly winding down into a slow-motion drone as Data forcibly shuts him down.
- Killing the Working Joe androids in Alien: Isolation will occasionally result in them reciting "to sleep, perchance to dream" in a much lower pitch — further distorted by the fact that the Working Joes often cough up white fluid as they die.
- In Dead Space 2 you're eventually forced to shut down ANTI, a malfunctioning AI blocking your progress through the solar array; after taking a plasma cutter to her internal mechanisms, the Electronic Speech Impediment sets in hard, resulting in a long procession of Max Headroom-style stuttering before ANTI finally winds down into a slow-motion drone and shuts down.
- After the player destroys the last of the personality cores in Portal, GLADoS's voice begins to speed up as she undergoes her fatal malfunction, rendering her Boss Banter in unintelligible chipmunk speech before she finally explodes.
- Appears in Psi-Ops: The Mindgate Conspiracy following the boss battle with Wei Lu. Having used her powers of illusion to pull a One-Winged Angel act, she reverts to human form after being mortally wounded; for good measure, she decides to deliver her last words in this state, her monstrously deep voice quickly returning to her natural speaking tone as she shrinks back down. Of course, given that she doesn't actually transform, this is presumably just for effect.
- The Spoony Experiment: Parodied in Spoony's playthrough of Phantasmagoria 2 when Curtis manages to prevent the Hecatomb from pulling a Grand Theft Me, destroying his psychic projection in the process. Spoony jokingly dubs the Hecatomb with Famous Last Words — groaning that his "emo powers" are fading, then belting out "craaaaaaaawling in my skiiiiiiiiin" in an increasingly lower voice before dying.
- Vinny of Vinesauce has a Running Gag in his streams where he does an impersonation of Arnold Schwarzenegger's character from Jingle All the Way who is "losing power" due to a lack of cookies. It starts off as a regular Schwarzenegger impression that gradually degrades into a very hoarse and raspy voice. The dialogue is usually his character begging his son to give him cookies.
- Aqua Teen Hunger Force:
- Batman Beyond: when his program is finally erased, Robert Vance's voice regresses back though childhood, stating progressively less impressive calculations until he's reduced to reciting "one potato two potato" in a child's voice, before calling out for his mother in the voice of an infant — then finally breaking down.
- In the Rick and Morty episode "Rickmancing the Stone", Rick attempts to get around Morty and Summer's absence by creating robot duplicates to take their place at home. Tragically, the Morty robot gains sentience — and Rick has no qualms about wiping his personality and dismantling him when the real Morty returns; the robot puts up a valiant effort to resist deletion but is ultimately overridden, resulting in his final screams dropping to HAL-9000 levels as his personality is erased.