Chirp Unlocks the Power of Sound

Clive Maxfield
|  Created: October 14, 2019  |  Updated: March 16, 2020

Chirp sends data seamlessly over soundwaves (Image source:

According to the Wikipedia, a chirp is a signal in which the frequency increases (up-chirp) or decreases (down-chirp) with time. It’s also the name of a rather interesting company, whose website can be found at

I don’t know about you, but – until recently -- if someone were to ask me how to transmit data from one device to another, my knee-jerk reaction would have been to suggest some sort of wireless connection. Unfortunately, this can be a lot easier to say than to implement. Well, the folks at Chirp have come up with a rather interesting solution, which is to transmit data over sound waves. As we see in this video, these sound signals can be anywhere from regular audio frequencies to the near ultrasonic, the latter being inaudible to the human ear.


Chirp offers a suite of software development kits (SDKs), which are free to use for free/open-source software, education, non-profits, and even commercial use up to 10,000 monthly active users (MAUs). In the case of the transmitting device, data in the form of an array of bytes can be passed to the SDK to be encoded as an audio signal and then transmitted via its speaker. Similarly, any device with a microphone that’s been augmented with a Chirp SDK can be used to detect and decode this audio signal.

Chirp offers a suite of software development kits (SDKs) (Image source:

One aspect of this that is particularly interesting for certain applications is the fact that – unlike wireless, which typically offers only one-to-one connections – chirp communications can be one-to-many; that is, when one chirp-enabled device transmits a signal, that signal can be detected and used by any number of chip-enabled devices in the vicinity.

Although it may not sound (no pun intended) like a 21st century solution, data-over-sound can offer a compelling solution for a wide variety of device-to-device (D2D), machine-to-machine (M2M), and person-to-person (P2P) applications.

What, you want examples? Well, I’m your man. Have you heard of Roblox? With over 180 million monthly users, this is a massively multiplayer online and game creation system platform that allows users to design their own games and play a wide variety of different types of games created by other users. Letting young gamers connect and enjoy shared mobile gaming experiences has traditionally been a challenge to do in a safe, fast, and straightforward way -- especially when multiple people need to connect at the same time or into the same shared gaming session. Well, as we read on this Roblox + Chirp page, the integration of Chirp technology into Roblox’s latest app version has greatly streamlined the device discovery process.

While I was chatting to Chirp’s chief technology officer (CTO), Dr. Daniel Jones, he happened to mention that Chirp had been deployed in a nuclear power station. It seems they needed to transmit data from one end of a large room to another, but they didn’t want to use a wired connection, and any form of wireless solution was an absolute no-no.

The problem with a wireless connection is that the power station was commissioned decades ago – long before today’s wireless technologies were available. Since this is such a safety-critical installation, you can’t simply add new technologies like wireless networks without recommissioning the whole system at a cost of tens of millions of dollars.

However, there’s no problem sending data over sound, not the least that the ambient sound in the room in question was over 100dB. Daniel told me that, in this case, they used near ultrasonic frequencies, because that part of the spectrum was relatively noise-free.

The folks at Chirp seem to be forming relationships with all sorts of companies. Just a few days ago as I pen these words, for example, I saw a Chirp + Linkplay announcement saying that Chirp and Linkplay Technology, a leader in Wi-Fi audio solutions, are partnering to deliver a turnkey solution for the frictionless, audio-based provisioning of smart-enabled consumer applications.

If you are interested in learning more about all of this, in addition to visiting the website, you can also download this whitepaper from the Arm website to discover why they believe “data-over-sound is an integral part of any IoT engineer’s toolbox.”

About Author

About Author

Clive "Max" Maxfield received his BSc in Control Engineering in 1980 from Sheffield Hallam University, England and began his career as a designer of central processing units (CPUs) for mainframe computers. Over the years, Max has designed everything from silicon chips to circuit boards and from brainwave amplifiers to steampunk Prognostication Engines (don't ask). He has also been at the forefront of Electronic Design Automation (EDA) for more than 30 years.

Well-known throughout the embedded, electronics, semiconductor, and EDA industries, Max has presented papers at numerous technical conferences around the world, including North and South America, Europe, India, China, Korea, and Taiwan. He has given keynote presentations at the PCB West conference in the USA and the FPGA Forum in Norway. He's also been invited to give guest lectures at several universities in the US and at Oslo University in Norway. In 2001, Max "shared the stage" at a conference in Hawaii with former Speaker of the House, "Newt" Gingrich.

Max is the author of a number of books, including Designus Maximus Unleashed (banned in Alabama), Bebop to the Boolean Boogie (An Unconventional Guide to Electronics), EDA: Where Electronics Begins, FPGAs: Instant Access, and How Computers Do Math.

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