Power Makes Your Voice Deep

When a person taps into some mystical wellspring of power, a common side effect is that their voice immediately plummets several octaves. Naturally, this is a tell-tale sign that copious amounts of ass is about to be kicked.

When pulled off correctly, the results can be spectacular.

If the subject is a woman, this usually presents itself in the form of their voices sounding huskier and more sensual (remember, Power Is Sexy), although there are cases where their voices just become deeper and booming like the men.

May be justified if the power upgrade comes with Hulking Out or transforming into a One-Winged Angel: being larger probably corresponds with longer vocal chords, which produce deeper sounds.

Sister Trope to Power Echoes, and the neutral cousin of Evil Sounds Deep and Voice of the Legion. It's not quite the same as Badass Baritone, although these two tropes aren't mutually exclusive.

Anime and Manga
"Kaiba: "Wait. Did your testicles just drop in the last five seconds or something? What the heck happened to your voice?""
 * In Seto no Hanayome, Unlucky Everydude Nagasumi turns into a Kenshiro Expy while under the influence of the Song of Heroes. Or just when sufficiently pissed off.
 * Yu-Gi-Oh: Any time Yugi and his Millennium Puzzle-residing alter-ego do a Mental Fusion, expect Yugi's voice to plummet faster than The Tower of Terror. This goes double for the dub, thanks to none other than DAN GREEN! (and it gets deeper over time). The voice is actually the Pharaoh's voice and is naturally that deep (so Yugi's just "borrowing" it) and in Yu-Gi-Oh GX, is shown to have the exact same voice.
 * Hilariously lampshaded in the first episode of Yu-Gi-Oh the Abridged Series by Kaiba.


 * Archer's voice in comparison to Shirou's.
 * In Bleach, this happens to Vizards when they put on their hollow masks.
 * In Rosario + Vampire, Inner Moka has a much deeper voice than Outer Moka.
 * Naruto's voice gets noticeably more deep while using Kyuubi's chakra.
 * Goku and Gohan's voices got noticeably deeper when they transform into Super Saiyans 3 and 2 respectively.
 * from Fairy Tail voice gets deeper while using her Take Over Satan Soul.
 * Also, Sawada Tsunayoshi from Katekyo Hitman Reborn when in Hyper Dying Will Mode.

Comic Books

 * In the Marvel Universe, Tyrone Johnson's voice became much lower when he changed to his Cloak superhero identity.
 * The comic versions of Ghost Rider all get deep, scary voices once they change from their human identities to that of the demon.

Fan Fiction

 * Subverted in 'Nexus'. When Jack’s in his demon form, his voice has a metallic edge; much like the Autobots.

Film
"The Riddler: "For if knowledge is power, then A God Am I!" (Beat) "Was that over the top? I can never tell!""
 * Blackheart from the movie Ghost Rider gets this magical power once he summons 1000 souls into his body. That may have been the only benefit from the whole deal; unless standing around getting blown up so you can slowly reform again is highly sought after in demon society.
 * Done for humorous effect in Batman Forever:


 * Galadriel's voice got pretty deep (and reverbed) in the first The Lord of the Rings film when she was imagining what she would do with the kind of power provided by the One Ring. However, Galadriel is already plenty powerful, so all the deep voice and special effects that went with it were her own doing.
 * In the book, her normal speaking voice is described as "clear and musical, but deeper than woman's wont."
 * When once again becomes the sea goddess Calypso in the third Pirates of the Caribbean film, her voice grows extremely deep and reverbed. It could be because she was also extremely pissed off.

Literature
"Number 1: I know. Less airy, more fairy, right?"
 * The High Seekers in the Novels of the Change, controlled by some unearthly force, sometimes go so deep that it's represented by boldface. This usually heralds the good guys getting a royal spanking.
 * Subverted in Artemis Fowl, when the characters expect this, but get a falsetto instead.

Live Action Television

 * Willow in Buffy the Vampire Slayer gets amped up on mystical magic powers and Alyson Hannigan speaks the character with a slightly lower and slower tone and speed.
 * Bailey from Suite Life on Deck when she got possessed by Princess Xaria.
 * Anyone in Stargate SG-1, when possessed by a Goa'uld symbiote, although it's actually the Goa'ulds invoking the trope. They can use normal voices if they want to, but they want people to think that they're all-powerful gods, so they change their voice to match people's expectations.
 * Merlin gets into this when Merlin begins speaking Dragon-language. His regular magic doesn't usually deepen his voice, but the dragon calls do.

Radio

 * This trope's roots may have sprouted from the old Superman radio dramas, in which the same voice actor used his tenor range for Clark Kent and his baritone range for the superhero. Most exemplified when, in order to show that Clark Kent was changing outfits, the voice actor would start out in his Clark Kent tenor saying "This looks like a job," then his voice would drop nearly an octave and he'd finish with "for Superman!"

Video Games

 * Soki in Tatsunoko vs. Capcom. For his Level 3 Hyper, he assumes his Black Oni Onimusha form, donning a mask with Red Eyes, Take Warning and a mane of white hair. His voice goes from "Boisterous Bruiser" to "Holy hell! He sounds like Satan!". Said voice is also booming and incomprehensible, but his voice drops from bass to baritone in no time flat.
 * In Devil May Cry 2, when Dante's health is at critical levels (his lifebar will be flashing red), activating his Devil Trigger will cause Dante to morph into a stronger, bigger, invincible alternate form (Devil Trigger Majin Form) able to mow do anything in the game with ease. While all of Dante's Devil Triggers echo (except for in the first game), this one has a much deeper, demonic sounding voice.
 * In Devil May Cry 3, manages to unlock the dormant power of the Sparda sword. Three guesses on what happens to  voice.
 * Nelo Angelo (aka ) has an unnaturally low voice. According to The History of DMC, Compare this to, where his original form had a slightly raspy, but still normal-sounding voice.
 * Arius, the Big Bad of 2 (the one nobody talks about), gets a deeper voice when
 * Invoked Trope/Enforced Trope/what?! in Jak 3, where the Precursors, revealed to be with not-so-impressive voices, use a voice-manipulating device to get that "uber powerful ancient" boom. They know they wouldn't be taken seriously without it.
 * In Guild Wars: Nightfall, voice becomes layered over a less high voice when.
 * When Link wears the Fierce Deity Mask in Majora's Mask, he physically becomes older, and therefore his voice becomes deeper.
 * In Viewtiful Joe 2, when is defeated, the Black Film controls/empowers him, warping him into the even more demonic . When the transformation is complete, his voice quickly deepens. Cue Round 2, where he has a slew of new tricks, more power and defense, and a much larger healthbar.
 * In Castlevania: Rondo of Blood, Dracula's voice deepens mid-word as he transforms into a massive bat-creature for the second part of the battle. Conversely, when that form is defeated, he roars in pain, and his voice spontaneously rises back to normal as his transformation is forced to revert.
 * Dracula's more recent cases of One-Winged Angel exhibit this as well, either during or after his transformation. Other examples include Symphony of the Night, Portrait of Ruin, The Dracula X Chronicles, and Harmony of Despair.

Webcomics

 * Lampshaded in the Order of the Stick prequel Start of Darkness. When Xykon becomes a lich, he expresses admiration for his new voice and repeats several James Earl Jones-isms.

Web Original

 * Inverted Trope in the Eskimo Bob episode "The Swarm". When Yuck absorbs all his clones and takes on his One-Winged Angel form, his voice actually becomes more high-pitched.

Western Animation

 * Mike Morningstar from his debut in Ben 10: Alien Force, where he uses the full extent of his powers after revealing himself to be the villain of that episode and siphoning off of Gwen's mana. His skin turns gold, while his voice noticeably deepens and gains an echo effect. When depowered, Mike's voice returns to normal. As Darkstar, however, it's back to said deepness, but this is a subversion, as it's an effect of his Cool Mask.
 * Both He-Man and She-Ra's voices get significantly deeper when they do their Transformation Sequences. Overlaps with Older Alter Ego.
 * The Superman Theatrical Cartoons did the same thing as the radio serials (using the same actor, no less).
 * In ThunderCats (2011), Lion-O's voice gets deeper whenever he uses the Sword of Omens and shouts "ThunderCats, ho!"
 * In Ralph Bakshi's animated Spider-Man series from the 1960s, two different voice actors play the voice of Peter Parker and the voice of Spider-Man. Guess which one has the deeper voice.

Other

 * Truth in Television, funnily enough. Men will subconsciously deepen their voices if they feel confident or superior to the person they're talking to. (And the other way around—if you feel inferior, your voice gets higher.) Has to do with establishing dominance. Hence, not only will a person with a very deep, gravely voice subconsciously be seen as a powerful individual, BEING powerful will also cause you to lower your voice without realizing it.
 * Male frogs and toads developed their extensible chin pouches so that their mating calls would sound deeper and more resonant. This suggests larger body size to females, which seek out the biggest males to father their offspring (because only males with a good set of genes live long enough to grow big).