Has a device been invented that can lower a person's voice by various decibels (as in the loudness of their voices)? This would be to enable silent communication as in whispering at a much lower rate people can hear. Or how would it work? I see some potential dangers in that technology but it also I think it would have some interesting applications I am not thinking of. (what I mean to answer with this question is a simple method for muting people's voices or enabling quiet interactions of people not using their voices).

For example, there are some sounds that humans cannot hear than other species and animals make and humans cannot hear them yet animals can. What if we had a reverse situation where humans cannot hear other humans? I have the articles below I found, for others to help give me their opinions. It's not telepathy but rather hearing people talking silently without being heard with conventional technology and people and still receiving messages from people talking.

Thanks for any answers offered in your replies and for your time.



An addendum I have added to this post: The reason of this post is to ask a question to see if I can write a story based on silent communication. The science is an idea on eavesdropping and muting people's voices. It would help create justice to eavesdrop in some cases in my conviction and silencing human voices can be problematic when used for the wrong reasons.

I know little of hard science and yet would feel a little bit intimidated to try to discuss it here with all of you here. I appreciate all the research and effort given in these below posts. I like asking questions to scientists who are generous enough to help me in the community and anyone who can help I plan to try something similar to: Low Notes on a High Level by J. B. Priestley. In the story he invents a device that can mute human beings. By lowering the sound of their own voices. It is very much appreciated all of what I have learned from others. (I had to modify the question as well as it was unclear). I want to try a modern spin on the tale.

Thanks for your patience.

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    $\begingroup$ Metallurgy could provide knives able to cut vocal cords, and sign language would let people communicate. $\endgroup$ – qq jkztd Sep 7 '17 at 3:35
  • $\begingroup$ About "silent communication". <a href="channel.nationalgeographic.com/year-million/">National Geographic year million</a> documentary has an episode in which humans are able to communicate my "mind messages" - send thoughts directly to other people, planet-wide. This tech does not prevent them from using their vocal cords, but extends our ability to communicate "telepathically" $\endgroup$ – andrew Sep 7 '17 at 5:10
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    $\begingroup$ lip sync I suppose $\endgroup$ – user6760 Sep 7 '17 at 5:14
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    $\begingroup$ I think you are making some confusion: the sounds we human cannot hear are ultrasounds or infrasounds, and they differ in their frequency, not in their level. $\endgroup$ – L.Dutch - Reinstate Monica Sep 7 '17 at 5:28
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    $\begingroup$ @andrew You can provide in-line hyperlinks using the [ text ]( URL ) syntax. $\endgroup$ – Frostfyre Sep 7 '17 at 12:27

Depending on the effect you want to implement into your plot you could use a laryngophone to reliably pick up whispers in a noisy environment (currently available technology) or rely on subvocalization assisted by sound restoration techniques (likely feasible today, but not an off-the-shelf product). In both cases you can then encode, compress, crypt and transmit resulting stream and send it where you need it.

A technology to "turn down volume" of human voice from outside AFAIK is not available (unless you want to use some "noise canceling" technology with an apparatus very near to speaker's mouth.

It depends on what you really want; a noise canceling apparatus coupled with a laryngophone could be what you need, but it needs to be on speaker body; I'm not aware of a way to do this "from remote" (i.e.: to point a "silencer gun" to someone and kill his voice).


With social media, typewriters, computers and books people can effectively communicate over large distances and over different times (I can read Philip K. Dick though he is dead for a while) without even the need of whispering a single word and being perfectly silent.

Also, there are devices which implement the speech-to-text and text-to-speech, which can be used for communicating over distances not coverable by simple voices.


The RPG Shadowrun had mobile phones with microphones implanted on one teeth so people talked with their mouths closed. Speakers were also implanted in the auditory canal. Although it was sci-fi when the game came up, I guess now it is quite possible.

Something that transmits vibrations and Morse Code could work, too.


You describe lip reading.

from https://www.lipreading.org/beginners-guide-to-lipreading

Lip reading allows you to “listen” to a speaker by watching the speaker’s face to figure out their speech patterns, movements, gestures and expressions. Often called “a third ear,” lip reading goes beyond simply reading the lips of a speaker to decipher individual words.

Learning to lip read involves developing and practicing certain skills that can make the process much easier and more effective. These include:

•Learning to use the cues provided by the movements of the speaker’s mouth, teeth and tongue

•Reading and evaluating the information provided by facial expressions, body language and gestures in conjunction with the words being said

•Using vision to assist with listening

•Using prior knowledge to fill in the gaps that can occur in understanding since it is impossible to read every word said.

Lip reading is no more a technological wonder than singing or signing or kung fu or any of the other things the human body and mind together can accomplish. Lots of hard of hearing people gradually pick up lip reading over time with no formal education (and maybe not even an awareness they are doing it). The technology is in formalizing the system to learn and use lip reading.

You can lip read a person who has no voice (for example someone who has had a laryngectomy). You can lip read if you are deaf. You cannot lip read in the dark, or a person who is facing away from you, or speaking a language you do not know.


There has been non-vocal communication for a long long time, and new methods are continuously being developed (we are using one now).

To effectively silence peoples voices only requires them to be unable to hear each other, not necessarily to be unable to speak. It is unclear why that would need to be a technological process, although it could be.

As an alternative hearing mechanism, check out haptic-hearing.


Wireless data traffic is better than sound

Speech is a form of communication. Communication is to take a thought in your head, transcribe that thought into a message, transmit the message over a medium (sound, paper, electrons, light) to another person, have that person transcribe the message back to a thought, and hope nothing got messed up in the process.

Speech as a communication method is a rather messy way of doing this and it has several weaknesses, one of which you mention: the lack of privacy. The communication channel through which the message passes — i.e. air — "leaks" the message all over the place and anyone within earshot can pick it up. Also the communication range is limited, it is easily jammed by noise, and the communication protocol (i.e. language) is rather limited and prone to lead to errors then translating to and from the message. The only reason speech is so pervasive in human society is because we come equipped with the tools to transcribe spoken messages — mouth and ears — from birth.

So instead of keeping doing more of the same, only quieter, we would be much better off with using technology to do away with speech, or at least the airborne channel of speech. And there is a wonderful technology for that: wireless data traffic.

For an example on how this can work in fiction, do take a look at the Ghost In The Shell franchise which uses this method frequently to let people talk with each other silently. Here is another example from the same franchise, that uses soundless speech even more blatantly.

Using wireless data instead of sound to transmit the message can solve the problem of eavesdropping in that the data can become encrypted. Also with the least bit of effort you can also hide the identity of who you are talking to, and even hide the fact that you are communicating at all. This is very hard to do with speech unless you just physically hide.

As for making a person's voice more quiet, it does not actually solve the problems. You are still transmitting the message in clear-text, in the open. Making it quieter does not make it secret or hidden, only slightly more obscured.


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