History Main / SecretIdentityVocalShift

A character changes voice while in costume. It is usually part of an attempt to disguise themselves. The voice change may be done by themselves, or done via external means, such as a mask or helmet with built in voice modulator. More extreme cases may have a second voice actor CastAsAMask to provide it.

* Shuichi Akai from ''Manga/CaseClosed'', was supposedly killed by Kir on orders from the Black Organization, only to resurface under the alias of Subaru Okiya, with a voice changing choker underneath his turtleneck sweater to alter his [[Creator/ShuichiIkeda distinctive voice]], even played by a different voice actor to complete the masquerade.

* ''Literature/SwordArtOnline'': In the anime adaptation of the Phantom Bullet arc, the normally shy Shino speaks in a slightly deeper, rougher voice when in-game as the ColdSniper Sinon. Meanwhile the DudeLooksLikeALady avatar that Kirito receives in this arc ''initially'' distorts his voice into a falsetto, but [[OohMeAccentsSlipping it's forgotten]] as the story gets more serious. In addition, Death Gun wears a mask that deepens and distorts his voice. [[spoiler:This helps conceal the fact that "Death Gun" is actually a shared identity. When Death Gun first appears, his manner of speaking is highly dramatic due to him being controlled by the young and impulsive Kyoji Shinkawa; but when Kirito encounters him later, his cadence is much softer and calmer, since he is controlled by the more experienced elder brother Shouichi.]]
** In the spinoff ''Literature/SwordArtOnlineAlternativeGunGaleOnline'', a number of characters have higher or lower voices in-game due to using avatars with a vastly different body type from their own, with one exception of Miyu who keeps her real life voice and mannerism when playing her small-sized avatar Fukaziroh.

** Also, in the early days this was used to HandWave why no one recognized him as Peter Parker when he was Spider-Man, because his mask muffled his voice.

* Senator Palpatine/Darth Sidious in ''Franchise/StarWars''. Palpatine loses the "normal" voice entirely after Mace Windu's attack, when he becomes Emperor.

[[folder:Fanworks]]
* In "Fanfic/TheLoudAwakening" when the mercenaries who Tetherby hires to kidnap the Loud children first capture Lincoln, they follow it up by getting the attention of the Loud sisters by sending them a picture of Lincoln who is in a white hospital gown, has his hands tied up behind his back and duct tape over his mouth, and is badly battered and bruised. There is also a letter that tells them they will get a call with further instructions. When they call Lori's phone, the voice of the lead merc is distorted to the point of sounding completely unrecognizable.
[[/folder]]

*** Oliver Queen uses a voice modulator that artificially deepens his voice. This not only keeps people from recognizing his celebrity voice, but also works to intimidate thugs suddenly faced with a murderous and guttural archer. When pretending to be the Green Arrow, ostensibly a new vigilante taking up the mantle, he changes the modulator's pitch to further sell the illusion that he's a different person.

* ''Series/Daredevil2015'': Matt Murdock has a change of cadence to his voice when he is costumed up as Daredevil. As himself in public, Matt has a jovial, easy going cadence, even in court. When in costume, he is much more terse and direct, which is noticeably different.

* ''Videogame/BlazBlue'': Hakumen wears a full-body armor and a deep, echoing voice courtesy of the armor. His voice is actually much softer, courtesy of him being [[spoiler:an alternate timeline Jin Kisaragi.]]

* ImpliedTrope in the ''VideoGame/{{Neptunia}}'' series when it comes to Uni, whose voice becomes slightly but noticably deeper as [[SuperMode Black Sister]]. Uni is one of only a handful of characters whose voice changes while in HDD, but unlike the others, she doesn't have the excuse of [[OlderAlterEgo becoming noticably older physically]] like Neptune, Plutia, and Peashy, as she is the only character who actually ''shrinks'' when in HDD. Combine this with the fact that none of the other CPU Candidates - Nepgear, Rom, and Ram - have their voices change at all when in HDD, and the implication is that Uni deliberately deepens her voice to compensate. [[PlayingWithATrope Played With]] when it comes to Uzume/Orange Heart. As Uzume, she has a deep tomboy voice, and as Orange Heart, she has a high-pitched voice to go with her more childish, innocent personality. It is later revealed that the latter is her true personality, and the former is a façade she puts on to keep people's hopes up, implying that, she too, intentionally deepens her voice.

* Also from DCAU, the Batwoman in ''WesternAnimation/BatmanMysteryOfTheBatwoman'' has a voice unlike her real identity, [[spoiler:that is, any one of the three]]. This overlaps with CastAsAMask as the Batwoman has a voice actress that doesn't voice any of the other characters.

* ''WesternAnimation/BigHero6TheSeries'': Hiro puts on a deeper, more "heroic" voice only when saving people who would logically recognizes his voice, such as Aunt Cass or Karmi. He has no problem with using his normal voice when talking to supervillains.

* In ''WesternAnimation/HeyArnoldTheMovie'', the mysterious informant "Deep Voice" has an altered low pitched voice. Turns out that Deep Voice is [[spoiler:Helga Pataki who used a voice modulator]].

* In ''WesternAnimation/SouthPark'', [[spoiler:Kenny]] deepens his voice when dressed as Mysterion. So do the other boys in their heroic (or in the case of Cartman, villianous) personas.

* ''WesternAnimation/WanderOverYonder'': When Wander becomes a Batman-esque superhero in "The Boy Wander", his high-pitched southern simpleton voice suddenly becomes deeper, husky and more serious.

* In the ''Film/{{Scream}}'' franchise Ghostface always uses a voice-changer voiced by Creator/RogerLJackson to disguise their identity, which changes with every movie.

* The UrExample is probably the 1940s RadioDrama ''Radio/TheAdventuresOfSuperman'', in which voice actor Bud Collyer shifted his speech down an octave whenever he switched from Clark Kent to the costumed hero. This carried over to his later work in ''Superman'' cartoons.

* [[Franchise/{{Spiderman}} Spider-Man]]: During the "Identity Crisis" storyline (where Spidey was framed for murder), Peter Parker came up with four new costumed identities, including the Hornet. After a new conference where the Hornet claimed "You won't need to worry about Spider-Man anymore", he was confronted by [[ComicBook/FantasticFour the Human Torch]]. Peter notes that he changed his voice as Spider-Man and changed it again as Hornet, but wasn't sure if he could fool the Torch, who was one of his oldest friends. Luckily, Johnny is more concerned about making sure that Hornet understands that Spidey has at least four very, very powerful friends, and that if he learned Hornet somehow harmed the webhead there'd be hell to pay.

* Franchise/{{Superman}}: Most versions of the character, starting with the 1940s radio serials but most famously in the adaptation mentioned in Film below, speak very differently as Kal-El than as Clark Kent: Generally he pitches the latter's voice slightly higher and affects a mild stammer, and sometimes hams up his Kansas farm-boy accent a bit, as well as altering his posture and body language to make himself seem smaller and less confident. Occasionally this is attributed to some sort of minor superpower involving "precise muscle control" or even low-key psychic powers, DependingOnTheWriter and continuity, but most versions explain it as Clark simply being a talented actor.

** ''WesternAnimation/SpiderManEnterTheSpiderVerse'' has Miles still doing it, and shows Gwen does the same when she's got the mask on, along with adopting a different accent.

* ComicBook/{{Static}} used his electromagnetic powers to distort his voice to the point of unrecognizability in his original Milestone run and initial DCU appearances. His [[WesternAnimation/StaticShock DCAU]] and ''WesternAnimation/YoungJustice'' incarnations lack this trait, and it would be abandoned entirely in his 2021 comic reboot.