Data over Sound – Alternative Data Transfer Methods

There are three mainstream data transfer methods as of now: the radio waves; copper/fiber conductor; and Bluetooth. The latter has a very small range and is too slow for data transmission and hence can be dismissed. The fiber conductors too need physical wires to be placed all over the country to be connected. It is possible but it is not feasible to connect most of the sub-urban areas and especially the rural areas lying far off the main cities and hence cannot be considered a good medium if we are to think about long-term data transmission.

Microsoft has been trying to use the TV signals’ whitespace (space left between two bandwidths) for providing Internet to remote areas. While it is a good idea, I guess if it pays attention to data over sound, many remote areas will have a better coverage. Read on to know how.

Data over Sound

Radio Waves and WiFi are harmful

GPS and Wi-Fi employs radio waves. While Wi-Fi has limits, radio waves don’t and that is why they are used for GPS. They are present everywhere and can travel fast to any area provided there are not many physical obstructions. Plus they can transmit in all directions and hence are popular for broadcasting. But radio waves are harmful. Some alternative must exist that can get us rid of harmful cellular waves and Wi-Fi signals. I was following use of light (photons) as a carrier for data but there has been no breakthrough as yet. But I came across a number of research papers when I decided to look into sound as a carrier for data and this page shares my understanding of the research.

Send Data over Sound – Advantages

To begin counting the advantages when you send data over sound, they are not harmful to living beings. Ultra high frequencies (inaudible to human ears may be harmful but I do not know how harmful they can be). Lower frequencies are much better – they won’t harm humans and can travel much farther owing to larger amplitudes. Like radio waves, they too travel in all directions and can be used easily for broadcasting.

The negative that I see is that they sound waves need a carrier for themselves – air, water, metal conductors so cannot be used in space or vacuum. That’s the only drawback and hence they may not be useful for GPS. Other than that, they can be perfect carriers for data without harming anyone with dangerous radiations as the radio waves and do. To know the extent of damage we are exposing ourselves to, read our article on hazards of cellphone.

Using Sound to Send Data over Sound

There can be three implementations to send data over sound. You can use amplitude modulation, phase modulation and frequency modulation. Out of all these three, amplitude modulation seems more feasible as it can be sent over low frequencies that are inaudible to human ears and thus, won’t create any humming sound or other distractions. Amplitude modulation also means sending data over longer areas as the sound waves with longer wavelength can easily bypass physical obstructions.

Since the digital data is binary, data can be easily mounted to sound waves by creating a short sound to indicate a 0 and a long sound to indicate the 1. At the receiving end, a demodulation (a modem) can be used to decode the message.

It is not that this is yet to be implemented. Companies in the area are already researching the cause to send data over sound and some have seen success though not complete. There are a number of issues, such as getting rid of additional sounds that the data may face while travelling on modulated sound waves. There may be attenuation and noise issues that have to be worked upon.

I would like to give the example of a startup called chirp ( It uses bird sounds for transferring data. It was crowdfunded and was overfunded by 118%. They have developed a system that you can get on Google Play or for iOS. The app is not yet available for Windows phone.

It is not necessary that you need to have an audible sound. The best method to send data over sound would be to use inaudible frequencies and low amplitudes that can span buildings and other obstructions so that they can reach far off places. Of course, we’ll need repeaters at places if the distance is too long. But it will still be better than using a balloon to provide Internet as sounds are everywhere unlike the balloons that are stationary for six months and move over to other place leaving the Internet-addicted people with nothing until the balloon comes back. Hope Microsoft works on this aspect of data transmission and comes up with something revolutionary.

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Arun Kumar is a Microsoft MVP alumnus, obsessed with technology, especially the Internet. He deals with the multimedia content needs of training and corporate houses. Follow him on Twitter @PowercutIN


  1. Bob Evans

    You do realize sound travels at a measely ~700 MPH. The latency would be huge. It would take the signal 5 seconds just to reach a tower a mile away. So if you tapped on a link with your phone, and the cell tower was 3 miles away, it would literally take 15 seconds at the minimum before the website server would even know you are trying to access it, then it would take another 15 seconds for the data to be sent back to your phone. Thats 30 seconds of latency, percievable speeds would be magnitudes slower than even dial up. Also if operating at signals below human levels of hearing (sub 20Hz), you would get incredibly low speeds. Like uselessly low speeds. 20HZ means 20 on/offs per second. That means 20 bits per second. At most. I’m sorry but this article is laughable, and I had to check the calender to make sure it wasn’t April 1st when I first read the title.

  2. Ger G

    Does the author have any concept of physics? There are so many things wrong with this article! There is no such thing as “longer amplitude”, there are longer wavelengths. Has he ever heard of echos, disturbance of animal life, propagation delays, useful bandwidth,…? Repeaters – please be slightly real. I suspect smoke signals would work better.

  3. Arun Kumar

    True. The speed of sound is 343.2 meters per second according to Wikipedia. But that is dependent on a number of issues like type of conductor, conductor temperature etc. Compressed sound moves faster at appropriate factors.
    Sound may be slower at lower frequencies but data can be modulated over different sounds and can be sent simultaneously. Don’t the current data transmission systems transmit multiple data chunks at a time? Why can’t it be implemented when it comes to sound? Also, it was my personal opinion that the sound should be inaudible.
    As mentioned in the article, some companies are researching the prospects. I am sure they did not hire people without expertise in sound. This is just a basic article about the concept of using sound as a carrier. I did get into depths of sound physics as most of our readers won’t understand the technical terms. But thanks for the comment.
    PS: You might also want to see:

  4. Arun Kumar

    The term repeaters used in the article is not the current digital repeaters you use at home. Talking in context of sound, they should be something that could help in remodulating data over sound and sending them forward in a better way. Please don’t connect it to WiFi equipments. The concept is wholly different.

    Also, when I say longer amplitude, I meant longer wavelength. I am sorry for that mistake. It will be corrected soon.

  5. visomvet

    What about animals? It may disturb a lot of species.

  6. Arun Kumar

    True that. But aren’t we already exposing them to harmful radio waves?

  7. visomvet

    Sure, just pile it on. Why not add to the burden.

  8. xrobwx

    The tech is in it’s infancy stage and just like anything (I started in 1993 with a 9600 baud 9.6 Kbps modem, now I’m on a 100 Gbps cable hoping for Google 1000 Gbps) it will grow with research and development.

  9. Arun Kumar

    If this gets properly researched and is implemented, the number of cellphone towers and other RF ground stations will go down. That will reduce the possibility of harm via radio waves. Then, it is also possible that audible sounds are pretty short and don’t hurt animals or anything. If voice is in form of birds chirping or something similar, the animals won’t be disturbed.

  10. Jim

    As a lifetime HAM Radio Operator…I can say without doubt you do NOT know much about radio , or GPS.

    Radio waves are only harmful to living beings when at very specific frequencies…or when living beings are in very close proximity to a HF antenna that is producing several thousand watts of energy.

    The RF signal from Wifi networks are far to negligible to be dangerous to humans or any other living creature.

    GPS does NOT use RF signals…GPS uses low frequency / low intensity microwaves that will only harm living beings when they are sanding directly in front of the emitter at a very close distance.The GPS emitters are located in low Earth orbit…the microwaves are completely harmless to humans.So unless you are an astronaut floating in in space in front of the emitter on a GPS satellite….you have nothing to worry about.

    Sound, no matter how it is compressed, amplified, or distorted, will ALWAYS travel at 700mph through the air. So, at best, data over sound would only be useful for short range communications, after that latency will become a real issue. RF on the other hand, moves at the speed of light…all but eliminating latency. You can NOT change the laws of physics…the max speed of sound is finite and there is absolutely no way to change it.

    HAM Radio Operators invented sending data over RF signals…decades before the internet was ever dreamed up…and it is still the best method used to day.

  11. Er Vicky

    is it possible to send sound waves over wifi

  12. David Mckenna

    Actually you can change the speed of sound with the temp and density of air and different substances carry sound at different speeds like water carry’s sounds faster then air.

  13. Tijn Kees Jacques Crevecoeur

    So should we pressurise the earth or submerse it in liquid? How the hell does saying it travels faster at different temps and densities help? IT’s not like it will be used in those situations. It will be used in air. Also Radio waves are proven to not be harmful, microwaves (frequencies above 300Mhz so what are phones use and wifi uses) are only harmful when hitting are body with several hundreds of watts for a prolonged period of time. so I honestly don’t get the point of this.

  14. Tijn Kees Jacques Crevecoeur

    No? Sound waves are pressure waves, they move through matter. Wifi is part of the electromagnetic spectrum (microwaves to be exact) it’s completely different and also not what the article is about.

  15. Tijn Kees Jacques Crevecoeur

    I really, really don’t get the point of this article. Cosmic radiation is where we get most of our radiation from. unless you live next to a cell tower RF waves are really not an issue. This technology is pointless and we to susceptible to background noise, much more so than RF noise.

  16. I agree on background noise. It tends to corrupt data. The article just brings your attention to research being done in this field. Somewhere down the lane, maybe they’ll be able to deal with background noise and may even find the mediums to transfer data faster.

  17. Tijn Kees Jacques Crevecoeur

    Good point, Maybe at a point it will be viable for certain things. I just don’t understand how it would benefit us.

  18. Victor

    I have just created a codec to send data over the air. I’m able to send 300 bps between 2 smartphones 4 m apart using just the ultrasonic band (18.5-20.5 kHZ). The infrasound is something very different, there isn’t enough bandwidth to modulate. Sound is a very harsh environment, amplitude modulation is the most affected one, frequency modulation is far more robust. I have been able to send data over 5kbps but between smartphones that are only 10 cm apart. I have worked for 3 years now in data transmission through sound and although it certainly has many applications and I don’t think it would ever replace wifi, GSM or GPS.

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