Using sound for transferring data is nothing new. In the 1940s, when IBM tried to solve the problem of how to use regular telephone lines to connect two computers, it figured out a way to convert data into sound, send the sound over the phone and then convert it back into data. (Yes, I'm talking about the modem.)
The benefit of using sound for data transmission was that equipment to handle the process was widely available.
In the wireless era, sound is still a great option for data transmission and other uses, and for the same reason.
Lately there's been a surge of innovations that harness sound waves to transmit data and do other creative things. Here's what's going on.
Some of the new sound-based technologies use ultrasonic frequencies -- sound that's too high-pitched for people to hear.
Google this month shipped a new guest mode for its Chromecast digital media player HDMI dongle. The mode lets Android phone users control a Chromecast without connecting the normal way, via Wi-Fi. Instead, the guest mode uses ultrasonic technology to communicate through a TV's speakers. The ultrasonic tech "pairs" the TV and the Android phone using a four-digit PIN code sent via sound. After that, the control takes place over the Internet (with the TV continuing to use your home's Wi-Fi and the phone using its own mobile broadband connection).
The beauty of this technology is universality. Every TV has the necessary "networking equipment" -- speakers. Every smartphone has the right stuff, too -- a microphone. That's all you need to transmit sound from one place to another.
A U.K. company called Chirp lets you send data via sound. The basic use case is to send a picture to someone nearby. (Both people need to have the Chirp app running.) Just take or select a picture, then click the yellow Chirp button in the app. The app makes a noise. If the other person accepts the picture, it appears on his phone.
What's really happening here is not that the picture is transmitted through the sound. The phones are simply pairing, and the picture is being uploaded, then downloaded, through each phone's respective Internet connections.
What's cool about it is that if 10 people have the app, all 10 can get the picture in the same way by all hearing the same sound. It's great for presentations, or even TV commercials, theoretically.
An app called Clinkle (for iOS and Android) lets you transfer money from one installation of the app to another. Each person's app needs to be preconfigured with bank or credit card details.
Clinkle has an interesting patent for something it calls Areolink, which is an ultrasonic method for transmitting money via sound from one phone to another.
Proximity marketing is when marketing content is transmitted wirelessly to people in a specific location. The trouble is, it's hard to have universal standards and get people connected to Wi-Fi or Bluetooth in, say, a store or a mall.
That's where Signal360 comes in. Its technology supports proximity marketing via sound.
Signal360's patented technology is designed to transmit marketing messages via sound. Through any speaker. For example, it can broadcast coupons over a store's PA system. It can transmit over TV commercials or through small speakers specific to a tiny aisle in a store.
Here's another neat trick: Signal360 can transmit code during a TV commercial or radio spot that's picked up by an app on your phone, which notifies the advertisers that you, specifically, have heard their commercials. With Signal360, an advertiser can then track you and determine that after hearing its radio spot, say, 12 times and seeing its TV commercial 30 times, you walked into a store and, after receiving an in-store promotion, bought its product.
The company claims that it costs about $150 per store to enable its technology.
The new generation of innovative sound-based technologies isn't all about data transfer. One company is using ultrasonics as a new kind of user interface.
A U.K. company called Ultrahaptics can add the sensation of touch to virtual objects that aren't actually there. It does it with ultrasonic technology.
OK, so imagine a holographic image, or an image superimposed on what you see through augmented reality -- or a virtual reality environment.
It's possible to use Ultrahaptics technology to enable you to touch virtual objects and feel what you touch. Let's say you can create a holographic ball made out of light. As your hand gets to the surface of the ball illusion, blasts of sound create something called "acoustic radiation pressure" in midair, and you can feel that pressure. By computer-controlling the vibrations in the air and matching them with the virtual illusion, the technology enables you to feel what you see.
(We'll be hearing more about Ultrahaptics during CES in Las Vegas on Jan. 6.)
But we do have to worry about hackers
As the use of sound as a networking technology grows more common, it becomes more likely that hackers will start using sound to gain unauthorized access to systems.
Symantec's John-Paul Power wrote a piece this month talking about the possibility of hack attacks on air-gapped systems. Air-gapped systems are PCs or networks that are not connected to other networks or to the Internet. It's generally believed that they offer the highest level of security.
Power warns that the way to hack an air-gapped network is to somehow infect at least one of the computers with malware. He mentions the tried-and-true method of somehow getting a legitimate user to infect the system, either knowingly or unknowingly. Once a system is infected, it's possible to use sound to make that system transmit to another computer beyond the air gap.
Of course, such a method could also be used to hack non-air-gapped computers and networks, and such a breach might be less detectable than a hack that goes through normal network channels.
The bad news is that sound-based hacking has enormous potential -- for exactly the same reason that all of the sound-based technologies mentioned in this column have potential, which is the ubiquity of speakers and microphones.
The good news is that the development of such exploits is very rare and still in its infancy.
Sound is a fantastic medium for all kinds of powerful things, from transferring data to further augmenting augmented reality with a sense of touch.
We're going to be seeing a lot more sound-based technologies in the years ahead. You heard it here first!