Vocalization has a number of features that make it a very robust natural form of communication:

  • Variable volume from whisper to shout, roughly scaling from direct to omnidirectional;

  • Equally effective in daylight and total darkness, doesn't require visual contact;

  • Precision of hundreds of distinct phonemic combinations;

  • Works over significant distance, even through/around some barriers.

Considering the possibilities of alien physiology and environments, is this as good as it gets or are there other methods as (or more) robust?


The bounty expires tonight so I'm going to go through some of the suggested answers below to illustrate how they fall short of vocal communication, in the hopes it will inspire more answers.

Remember: I'm not saying it's impossible for these forms to evolve, I'm saying they are fundamentally more restrictive than vocalization.


  • Prevailing wind conditions limits the direction of communication. "Speaking" to someone upwind of you could be impossible, even over a short distance in a light breeze.


  • Speaking to someone out of arm's length would be impossible, and the ability to speak to multiple people is limited to the number of appendages you have.

Bioluminescence/infrared/skin pattern

  • Requires visual contact by the recipient and a narrower range of ambient lighting conditions, and may be impossible during the brightest part of the day or at night/in darkness.


  • This also requires visual contact, but even more restrictive is the necessity of writing media and tools. It's also arguable that any form of natural communication can develop written/recorded forms, so a writing-only language would be inferior to all others.


There are a few references to electromagnetic communication (such as, but not just, radio) I think are begging to be explored more. Such a mode of communication could penetrate barriers and distances that stop vocalization and conceivably allow greater directionality (e.g. the ability to "whisper" to someone in another room, to speak to someone at the bottom of a pool, etc). But can a case be made for it evolving in nature?

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    $\begingroup$ Telepathy might be better, direct transmission of thoughts, you could adjust the strength, have it target individuals or groups, you can make it as powerful as you want to. $\endgroup$
    – Shadowzee
    Dec 7, 2017 at 4:36
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    $\begingroup$ Do you count whistling as vocalization? People in the Canary Islands have a whistling language (counted as a subset of Spanish), which is much better at carrying a message long distances across a valley (up to 5 kilometers!). $\endgroup$
    – Flater
    Dec 7, 2017 at 9:36
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    $\begingroup$ Whistles (and clicks) are integrated parts of other otherwise typical languages, so I would count that as vocalization. $\endgroup$
    – rek
    Dec 7, 2017 at 14:51
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    $\begingroup$ You should add what do you mean by robust here. $\endgroup$
    – Vylix
    Dec 7, 2017 at 15:21
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    $\begingroup$ I'm using a method of communication right now that's a bit faster than speech (providing you're a decent reader and typist). Presumably aliens could develop it naturally. $\endgroup$
    – Dan Staley
    Dec 7, 2017 at 21:42

10 Answers 10


Effective communication really depends on what your creature abilities are and the constraining environment, as you have said.

Vocalization seems to be the most robust because we use it daily to overcome the need of visual contact. Have you considered sign language, or gestures as communication method? It works through noisy situation.

So, rather than sound is better than gesture, both are complementing each other. When the sound communication is limited, you can use visual communication, and vice versa.

You can also try to devise smell language or taste language. Animals have already used smell of pheromones to mark territory, so it's a more efficient form of communication in term of asynchronous communication, similar to leaving an email for your friend to read later.

As for taste language, well, just imagining it would be weird. Try imagine two aliens French kissing each other, while their saliva tells their partner what they are feeling right now. This saliva might contains hormones that tell the partner their emotion state (happy, sad, or angry - well, it's difficult to imagine someone's angry and kissing each other)

Or you might want to try tactile signing as tactile language (weird, yeah). Deafblind people use that to communicate. I feel very weird when I see it at first. Here is a video of tactile signing: Tactile signing for deafblind and Soccer tactile signing

tl;dr Is there anything more robust or not, it depends on the environmental barrier and the senses your alien. You can try to combine languages from the five senses, or even create a sixth sense.

Note that telepathy is basically cheating in my opinion, because it allows you to communicate over distance disregarding environmental barrier (visual or auditorial). But that just depends on how you define the telepathy.

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    $\begingroup$ Telepathy as EM communication, kind of biological radio, wouldn't be cheating, right? $\endgroup$
    – Mołot
    Dec 7, 2017 at 6:54
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    $\begingroup$ Might you be thinking of Shared language between humans and wolves - Alternatives to scent? $\endgroup$
    – user
    Dec 7, 2017 at 8:20
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    $\begingroup$ Re. smell and taste language: They can be extremely sophisticated, seeing as how e.g. ants can not only lay down paths to follow but also emit signals warning other ants of danger and even calling for assistance in different tasks. Similarly, honeybees communicate very detailed information through repeated patterns of movement... which also might fall under a broad interpretation of this answer's mention of "sign language". $\endgroup$ Dec 7, 2017 at 11:14
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    $\begingroup$ Well, your vocalization won't be able to function in vacuum, or windy areas, or noisy place. It is prone to noise cancellation. All method of communication has their own weakness. If you want a method of communication that transcends any barrier, you are looking for some kind of Hive Mind, or united consciousness. $\endgroup$
    – Vylix
    Dec 7, 2017 at 17:48
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    $\begingroup$ Another example of tactile language is the tap code used by american prisoners of war in Vietnam. $\endgroup$
    – JohnEye
    Dec 7, 2017 at 22:16

The visual signaling of cephalopods has promise, signaling through pattern and color change in the skin. Their only limit is their poor color vision, which you could change. Bioluminescent animals could communicate in the dark. Distance is even better than sound since they are limited by line of sight only.

They can even hold two conversations at the same time. Look a this picture with one pattern being shown to a female and another being shown to a rival male. Sight does get drowned out so many many conversation can be happening at the same time.

male and female cephalopods (and an arrow indicating a second male to the right), where the male has two distinct patterns - one in the direction of the female, the other in the direction of the rival male

Source: https://www.wired.com/2017/02/squid-communicate-secret-skin-powered-alphabet/

  • $\begingroup$ better for distance, worse when there's obstacles :) $\endgroup$
    – Syndic
    Dec 8, 2017 at 12:05
  • $\begingroup$ on the other hand its hard to drown out sight. $\endgroup$
    – John
    Dec 8, 2017 at 22:18

You can try Wi-fi. Or more generally, radio wave.

You just need a natural antenna. After some research, I found nothing similar on Earth (sorry !). But in alien settings, you can make your specific radio wave organs (an emitter and a receptor).

It wouldn't be this incredible when you think of the feats of engineering life is capable of on our own planet. Think of bat's echolocation or electric eels' capacities. Some fish can generate electromagnetic fields, too. Animals can already adopt a lot of physic phenomena to suit their needs.

The pros of this (compared to voice, for example), are multiple. A very long range can be attained depending on the frequency and the power used. The data transmitted could also be very rich and I think the main limitation is the brain capacity of your alien, for interpreting and composing these signals.

Almost every properties of those signals are adaptable in a worldbuilding case: range, bandwidth, power. This could be quasi-telepathy or just a 30 meters limited communication.

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    $\begingroup$ You might be surprised to discover that most animals have built-in detectors for EM waves. They're called "eyes". Just remember, while building your aliens, that wavelength scales with detector length, so to have an "eye" that receives radio waves you would need to have much bigger detectors. $\endgroup$
    – BgrWorker
    Dec 7, 2017 at 10:43
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    $\begingroup$ @RonJohn Again, think back to life on earth- we see visible light, an EM wave. There are plenty of creatures that produce visible light as well - fireflies, certain beetles, a massive variety of glowworms. Not to mention that every person and animal on the planet generate infrared radiation constantly. I do grant that lower frequencies (like 2.4 GHz Wi-Fi or microwaves) are much more difficult to generate organically, as artificial EM applications use magnetic metals. But all that to say, it's not inconceivable. $\endgroup$
    – automaton
    Dec 8, 2017 at 14:16
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    $\begingroup$ Ultimately, writers are writers. They aren't Ph.D. Radar engineers, and even so, an exact scientific description of how a Wi-Fi organ works would probably get in the way of the larger story. I think it's a matter of storytelling to make it sound plausible without inventing an organic EM transmitter. Well-placed vagueness can be your friend. $\endgroup$
    – automaton
    Dec 8, 2017 at 14:18
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    $\begingroup$ @RonJohn An electric eel? $\endgroup$
    – DrMcCleod
    Dec 8, 2017 at 15:55
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    $\begingroup$ @DrMcCleod that would be a good source of electricity. qrg.northwestern.edu/projects/vss/docs/communications/… The two problems I see are (1) the wire -- which is solvable --, and (2) the necessity to continuously create bioelectricity (the eel requires 20 minutes to recharge it's electric organ). $\endgroup$
    – RonJohn
    Dec 8, 2017 at 16:21

Are there any natural forms of communication as robust as speech/vocalization?

genesis in Hebrew

Speech / vocalizations are good. But writing is better. Writing has permanence, which is not true for any sounds or gestures produced by a creature. You cannot read in the dark, but you can wait for it to get light. You can refer to a written communication again and again. You can add to it. You can translate it. Maybe I cannot speak to you at the time, but I can pass you a note. You can read it, fold it up, and read it again later. You can leave written words for others to read and consider, exactly as I am doing now.

Writing is an immense achievement. Does it count as a natural form of communication? Right now I am typing on some tech miracle, but I can write you a note on a rock with my finger as a pencil and mud as ink. That seems pretty natural to me.

  • $\begingroup$ I considered adding a point about ease of translation/recording to other formats like writing, but that would likely be true of any form of communication. However, as a comm. form writing-only has numerous drawbacks: it requires line-of-sight, sufficient light, specific materials (and the time to use them), and is largely divorced from context. If you were running from a tiger and needed to warn people facing away from you but ahead of you on the path, there's no way you'd choose writing over shouting. $\endgroup$
    – rek
    Dec 7, 2017 at 15:06
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    $\begingroup$ @rek: On the other hand writing has the immense advantage that is can transcend time. The book of which this answer contains a picture of the first paragraph is more than 25 centuries old. $\endgroup$
    – AlexP
    Dec 7, 2017 at 16:27
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    $\begingroup$ For humans, writing was an evolution of vocalisation. It was a formalisation of our spoken languages. Humans didn't invent "written words" then decided to give it a meaning and a sound, it was the other way round. Writting is the equivalent of the first tape recorder $\endgroup$
    – Hoki
    Dec 8, 2017 at 12:13
  • $\begingroup$ @AlexP That's about the only advantage it has. $\endgroup$
    – rek
    Dec 8, 2017 at 18:45
  • $\begingroup$ @rek: It also had the immense advantage that it can transcend space. KIngs and emperors relied on couriers carrying letters to spread their words far and wide, and to receive reports from the four corners of the world. $\endgroup$
    – AlexP
    Dec 8, 2017 at 19:46

There are some environments where speech communication does not work:

  1. Vacuum: Speech needs a transport medium like air or water. In the absence of a transport medium, speech communication cannot be used.
  2. Noise: In a very noisy environment (think of permanent thunderstorms or permanent earthquakes) the cost of producing a loud and clear sound signal may become too high to be effective
  3. Presence of enemies/predators: The sound signal is "for everyone", it is not possible to bundle it in a laser-like beam to a target recipient.

Having said this: As life on Earth clearly shows, sound signals are the means of communication of choice for many lifeforms. Other kinds of signals (Bee's dances, chemical markers (ants), optical signals) play only a minor role in communication, but they aren't completely ruled out. No life form we are aware of uses radio waves for communication naturally, this tells us something. Maybe radio waves will be used by life forms that can go out in the vacuum.


Speech is sound waves transmitted by air for which humans have evolved a receiving and interpreting system so they can use it for communication. Technically, any length and type of wave that can carry the signal, be transmitted and received within the environment and translated with precision could replace it. Imagine the same principle but with light instead of sound, or X-rays. Aliens could communicate with very complex QR codes for example, even moving ones. I think it only depends on the environment you want to create what kind of communication would have evolved.


On a physics point of view, you could consider the four fundamental interactions of the standard model:

  • Strong (bonding quarks together)
  • Electromagnetic (light, sound)
  • Weak (interaction with neutrinos)
  • Gravitation (interaction of planets)

I suppose physically sending a written message or using the transfer of matter can count as using matter cohesion, so strong interaction. Electromagnetic is what is used in our world for non-written or numeric communication, through light and sound signals.

Detecting weakly interacting messages needs big amounts of mass and is a very noisy process (for instance building neutrino detectors with huge pools of water). Producing gravitational waves involves catastrophic events, such as destroying stars, and are also not easy to detect. Because these signals can travel for years in the universe while barely interacting, on gigantic time and space scales they could be efficient to communicate.

On our scale, choosing electromagnetic signals is definitely a sound choice.

  • $\begingroup$ Using gravitational waves seems promising. You don't need to worry about requiring supernova to produce waves, as long as the target can detect the shifts. It seems plausible in deep space where there are few stars. $\endgroup$
    – Vylix
    Dec 7, 2017 at 13:14

Even humans have other ways of communicating, but we are not rationally aware of them. Human non verbal interaction

As such, some aliens could have very developed pheromone glands and could control their release. So you could get to use it as a language.

Electromagnetic could also work, if the alien would have a specialized organ to perceive such changes.

  • $\begingroup$ Glands: see the beginning of Scalzi’s Electric Sheep. $\endgroup$
    – JDługosz
    Dec 8, 2017 at 14:12

If you proposed an alternate communication it would have to be able to communicate danger warning to start with as this is widespread among animal groups of many types.

I assume we are talking about a cooperative "people" with social organization. Vocalization transmits feeling and fears and joys, excitement, child care, bonding, all that. Language was just an outgrowth of that when someone was grunting enthusiastically and another said, "What is it this time?". Yep, that was the first sentence in human history.

Would/could written language come about without first being spoken? Music, song and dance are also supposed to be quite fundamental to our social origins and shared experience.
Are these folks of yours deaf?

I accidentally spent a lot of time with Mayans in their tiny village. Not much talking ever went on (though I hear they do more of it now with tourists about). But they lived very simply and in small groups. Diet and activities were the same from day to day and could be shown, and thereby taught, through demonstration.

I also lived with Navajo and Filipino families that used borrowed words for anything complex or technological (down to the level of "furniture" or "dishwasher").

So my two points are that emotional communication is difficult without sound and technology is limited without conversation.


Infrared Communication:

Perhaps your aliens have the ability to see infrared, and control the temperature within parts of their bodies. Consider then, how cool it would be if they communicated by changing the "heat pattern" within their bodies to communicate their thoughts and feelings with one another. Maybe even, they could alter the temperature of the air around them to get the attention of one another when they aren't actively "looking" at each other. A blast of hot or cool air means "HEY PAY ATTENTION!!"

This would fit the conditions of:

  1. Being able to scale (they could run hotter or cooler).
  2. Being effective in night or day (you can see through an infrared lens in night or day scenarios)
  3. Having a variety of precise and distinct characteristics within their "language" (variances in heat patterns)
  4. Working over significant distances (you can see heat traces through infrared from far away and through some barriers)

Vibrations Through Touch:

If you want to discuss a form of communication that might be similar to speech/vocalization, but slightly more alien, one method could be "hearing" through a sense of touch. Someone can feel you blow air on them from a distance, and you can theoretically alter the scale of air you release as well as the pattern. I understand that this is almost exactly how hearing works (pushing molecules through the air in different frequencies and patterns so that our ear drums vibrate and communicate the meaning to our brains), but it seems more alien when you consider "hearing" through the sensation of touch on your skin.


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