Colonel Sandurz: What is it?
Technician: Can I talk to you for a moment please, sir?
(Dark Helmet and Sandurz walk across the bridge to his station)
Technician: I'm having trouble with the radar, sir!
Sandurz: You don't need that, private! (takes the communicator and puts it back on its hook) We're right here, now what is it?
Technician: I'm having trouble with the radar, sir!
Dark Helmet: (angrily grabs and throws the communicator away) NOW WHAT IS IT?
Technician: (normal voice) I'm having trouble with the radar, sir!
Whenever we hear someone talking through a radio (or any sort of communications device) their voices are always, always slightly distorted so that the audience can tell that the voice is being received through the communications link (as opposed to being spoken by someone who is slightly off-camera). This occurs even on shows where the builders of the communications devices in question achieved faster-than-light space travel hundreds of years ago and who by all rights ought to have come up with a perfect-fidelity microphone/speaker system long ago.
The effect can be accomplished by running the audio through a bandpass filter to remove all frequencies outside a specified range. For example, the U.S. telephone network uses a filter that keeps only frequencies between roughly 300 to 3500 Hz. It's symbolized in comic books by adding a jaggey or "lightning bolt" effect to some part of a speech bubble.
Variant: Voice communication over any kind of magical or psychic link (e.g. telepathy) will have a different effect, making the voice sound spooky or echoey instead of metallic, but the trope is the same.
This may be simply to serve the Rule of Perception, because otherwise we might get confused as to who's where. It also has a good technical reason: transmitting only 3 kHz worth of audio is far easier than transmitting 20 kHz regardless of what transmission medium or method is being used, and it's OK to do this when the only thing that matters is the speech itself and not so much the audio quality. This may also be explainable in-Verse as a user interface feature; the fictional designers of the fictional system may have felt it was useful to be able to distinguish radio voices from the voices of people present in the room.
- The in-head cyber-telepathy used in all Ghost in the Shell media (except manga, obviously) recycles a distinctive filter set from The Movie. It's basically just a spatializer, designed to make the sound seem far away, in a way different from a standard reverb or echo.
- Used in Prétear for all of the scenes that allow us to listen to Sasame's "Words Gate" radio show. Particularly notable is when Mawata is listening to a recording of his show, only for her player to run out of batteries as Sasame's voice comes in loud and clear to repeat what he said on the show—in person.
- An almost meta-example: The Firesign Theater regularly used these sorts of techniques for their many Shows within a Show on their albums, which generally parodied old-timey radio. Lampshaded when Nick Danger (Third Eye) is asking himself a series of questions about the mystery he's trying to solve, and ends with: "and how do I make my voice sound like that?"
- The voice of Korben Dallas' Taxi in The Fifth Element sounds like a late 90s speech synthesizer. And radio/television communications are hardly better (though you wouldn't be able to tell with Ruby Rhod anyway).
- Used in the Star Wars movies, in particular the first movie with the attack on the Death Star, where the distortion was filtered through what sounded like a single sideband transmitter. Star Wars Legends suggested that this was at least somewhat deliberate on the part of the Rebellion, as it naturally disguised their voices (and being rebels, they would prefer to keep their identities unknown or at least plausibly deniable) and they'd rather use their limited bandwidth for things like better encryption, frequency hopping, etc than high fidelity. Though they say very little, the Imperial pilots' voices are significantly less distorted.
- And any time a stormtrooper talks, his or her voice is flattened and made to sound a little more artificial. It's supposedly the speaker in the helmet. Droids, too.
- Truth in Television if you use a voicemitter mounted on a gas mask. The first time you wear one, it can be very difficult not to talk about missing droids or transferring prisoners to holding cells.
- Particularly bad in the Mystery Science Theater 3000 featured movie Monster a-Go Go, prompting Crow to riff "take the kazoo out of your mouth!" and "They're talking to Charlie Brown's mom!".
- Played straight in The King's Speech, Truth in Television for its day.
- THX 1138.
- Parodied in two films by Mel Brooks:
- High Anxiety: When Thorndyke asks his secretary to repeat her intercom message without holding her nose, she replies in a perfectly normal voice.
- Spaceballs: The "jammed radar" scene featuring Michael Winslow as the Spaceball manning the radar station. Dark Helmet also talks this way whenever his visor is down.
- In 20 Years After Michael does radio broadcasts to be friendly and upbeat in the post-apocalyptic world caused by a nuclear war and a plague.
- Star Trek, all series. Beam living people from one place to another? Check! Perfect the fully immersive, utterly realistic holodeck? Check? Build a communicator that can transmit sound with better quality than an FM radio? Still on the to-do list.
- Battlestar Galactica (2003) may be an instance in which this trope is justified; except for having artificial gravity and the jump drive (which is, admittedly, a big "except"), their tech isn't any more advanced than real life. It's with noting that their civilian radios, having a greater emphasis on fidelity, don't sound nearly as bad as their military comms.
- The original Battlestar Galactica (1978) also featured this effect in inter-ship communications.
- Star Wars' fighters had the same effect for their military radios. It's a close simulation of the actual sound of single sideband radio, as still used by ham operators today, and military voice comms a few decades ago. Besides the "telephone filter" there is a slight, and changing, pitch shift.
- Used in the Doctor Who episode "Silence in the Library"/"Forest of the Dead", when Charlotte watches what's going on on the TV. Particularly notable because the background music accidentally had the same treatment applied to it. (Or maybe not so accidentally. It's actually a subtle hint that she is actually the main computer in the library and is subconsciously controlling everything, and since it's a chase seen on the TV it should have chase music.)
- All the callers to Frasier's show, which is quite logical (and disguises the fact that many of them are uncredited cameos). Interesting in that some of the dialogue for those scenes is written, some is ad-libbed to give it a more believable feeling of sponteneity.
- The Goodies. When Bill and Tim are sent on a rocket to the Moon, they keep saying "beep!" at the end of every sentence while communicating with Graham at Mission Control, to imitate the Quindar tones.
- Musical example; on Pink Floyd's Wish You Were Here album, the end of the song "Have A Cigar" is distorted to sound as though it's playing on the radio. This leads into a sequence where the radio is tuned through several channels rapidly before settling on the opening riff of the title track. Eventually, a second guitar joins in undistorted, symbolising the listener (ex-frontman Syd Barrett) playing his own guitar along with the radio.
- Live they would sometimes have the main riff of "Wish You Were Here" played on an actual radio.
- "Honey Pie" by The Beatles, for the single line "Now she's hit the big time!"
- In the song "Patterns" by Simon & Garfunkel. After "The pattern never alters, until..", "The rat dies" is heard in Radio Voice.
- Several of Doctor Steel's songs have epigraphs, some sampled from old Public Service Announcements such as "Duck and Cover", others deliberately done as a parody of such announcements.
- In Starship's song "We Built This City", about 2/3 of the way through, the song breaks for a radio-style announcement of an advert for a San Francisco radio station with a very much radio sounding voice (done by veteran DJ Les Garland).
- Kraftwerk's Autobahn features a radio being turned on partway through the song and the vocals are distorted to sound like a radio transmission drifting in and out of tuning.
- The music video for "Cruise Control" by New Zealand band Headless Chickens is set in a car. At one point the lead singer stops singing and a male member of the band speaks his lines via a CB radio. Even when he's not speaking into the microphone but to the audience, he continues using a Radio Voice.
- Truth in Television - er, I mean Radio: Some BBC Radio productions achieve the effect of a radio voice by the simple yet obvious expedient of feeding the voice through an appropriately-sized loudspeaker.
- In the radio version of The Shadow, the audio cue for "Lamont's turned invisible now" was the same filter used for "This character is talking over the telephone". Which somewhat limited the scriptwriters — Lamont Cranston could get phone calls from other characters, but could only call other characters (and be heard over the line from their POV) as The Shadow.
- The Firesign Theater "Nick Danger" radio show parody has the title detective's inner monologue played in a tinny effect.
Nick: That reminded me - how did she get mixed up with that sleazy weasel Rococo? And...how do I make my voice do this?
- The Halo series. When Cortana is in her holographic form or in your helmet and talking to you, her voice is perfectly natural, but when she's speaking to someone else through your radio, her voice distorts—even though you're hearing her through the same set of speakers.
- The marines in Half-Life, as well as the Combine guards and soldiers in Half-Life 2.
- The Combine are speaking through a vocoder, sugically implanted as part of their conversion from human. The modulation is intentionally done. Marines still have no excuse, except maybe Rule Of Cool.
- This is averted for the soldiers in Half-Life: Opposing Force, as every NPC soldier you meet speaks without using a radio. Played straight however when you actually use radios to listen in on soldiers who aren't with you.
- In Mass Effect and especially its sequel, Commander Shepard and squad will walk around on alien planets and cities in full battle armor, with the player given the option to wear a helmet or show the character's face. In the second game, there is a subtle but noticeable filter between Shepard's normal voice, and how it sounds when s/he's talking with the helmet on (And depending on the type of helmet currently equipped, it might even show blinking lights at the mouthpiece which move in time to his/her voice).
- And of course Tali's voice always has a slight buzz to it, which is very noticeably gone in the few scenes where she takes her helmet off.
- The high-tech quantum entanglement communicator the Illusive Man uses to speak to Shepard in Mass Effect 2 notably does not have any kind of distortion effect. The somewhat more utilitarian models of the same device used by the Alliance and Cerberus in Mass Effect 3 have a filter, but much less of one than standard communications.
- Helmeted Space Marines in the Warhammer 40,000: Dawn of War series have a distinct metallic ring in their voices. Talk into a metal mixing bowl for the best Astartes impression.
- Used subtly in the Modern Warfare games. Your team mates voices pick up the Radio Voice effect if they happen to be farther than a short distance from you when they are talking.
- Most characters in Star Wars: The Old Republic who wear full helmets have more or less modulated voices to go with their headgear, including players and their companions.
- Marvel Heroes uses this with Iron Man, Doctor Doom, and Ghost.
- Borderlands 2 and Borderlands: The Pre-Sequel! make good use of this trope to avoid a common RPG speedbump. If you walk away from someone who is delivering quest dialogue, it will crossfade to a bandpassed version that remains at a constant volume wherever you go. The characters automatically switch between Radio Voice and normal voice to stay audible.
- In one episode of The Daily Dredge, an interview guest starts talking sounding as if he's on the telephone - until John reminds him that he's actually in the studio with him.
- In Episode 1 of The Orbiting Human Circus (of the Air) as a radio listener searches through stations and the eponymous radio Variety Show opens, the "on-air" audio acquires a mildly tinny, distant quality, including protagonist Julian the Janitor's interruption and the ad break The Host cuts to as a result. Throughout, Julian's personal Interactive Narrator recounts the proceedings in clearer tones, including Julian's forcible removal from the stage and its concealment from listeners by the ad break.
- Parodied in an episode of Invader Zim, where a policeman is driving down the road and hears an utterly unintelligible static-choked mumble from his radio. The policeman picks up the handset and talks into it in an equally meaningless Charlie Brown-esque mumble, revealing that it's not actually radio interference—in this world, cops just talk like that. Both sides can apparently understand each other perfectly.
- Ben's various forms in the original Ben 10 series were typically voiced by different voice actors than human Ben. For the bulk of the series, the only exception was the technology-based alien form, Upgrade, who spoke with Ben's voice with the Radio Voice distortion effect.