back to article Chirp! Let's hear it for data over audio

Low tech sometimes succeeds where high tech fails – as one ingenious company is proving. Chirp sends data over sound, a burst of audio that usually sounds like a bird’s tweet. It doesn’t transmit much data – 50 bytes – but it turns out you don’t need much bandwidth to bridge the gaps between the real world and the digital …

  1. Tom Chiverton 1
    FAIL

    " a Chirp to a Wi-Fi router to authenticate and join the network. You may not want that to be audible"

    The fuck. If the router can hear it, so can my phone !

    1. Mage Silver badge

      WiFi pairing

      Short range two way IR would make more sense.

      1. Deltics

        Re: WiFi pairing

        Too directional and requires a clear line of sight.

        1. Charles 9

          Re: WiFi pairing

          Which is good because proper protocol should demand you be right next to the bloody thing when trying this. A cheap but short-range protocol that nonetheless is tough to get through walls (quick chirps will be hard to record through the attenuation of your average wall) would be a good thing.

          But then again, why not a QR code, which is silent and also requires immediate physical presence to use?

          1. Daniel Jones (Chief Science Officer, Chirp)

            Re: WiFi pairing

            Thanks for the comments. You're absolutely right that QR codes can be (and are) used to similar effect. Using audio, however, means that there's no need for line-of-sight, or any need to do any fiddly alignment of the barcode with a reader - you just need to be within hearing range. This seems like only a minor improvement, but it results in a pleasingly effortless user experience.

            And the range can effectively be controlled by setting the volume of the router/mobile, so the admin can configure whether you to be metres or centimetres from the router for authentication to succeed. So you have the option of "right next to" if you want it.

            And finally: "audible" should definitely be read as "human-audible" - the router/phone can absolutely hear the tones or the communication would not be very successful!

  2. Grumpyrocker

    I already own some devices that send data via sound in this way. These are TC Electronic guitar effects pedals. Users can download new settings and sounds in a phone app, then transmit these settings by holding the phone close to the guitar's pickups. The chirp is heard by the pickups, sent down the cable and changes the sound of the pedals. It's a really neat system.

    1. Charles 9

      I know some Yamaha receivers that can do firmware upgrades using encoded sound files. You have to download the sound which is usually a CD-quality WAV file and find a way to play it back into the receiver through an audio pickup (usually by burning it to a CD player, setting the receiver to that device, and playing back the track).

  3. Crazy Operations Guy

    " In nuclear power station control rooms, radio devices have been banned since the 1950s because of concerns about interference. No Wi-Fi or Bluetooth is permitted. Chirp can talk to the machines safely."

    Yes, but shielded cable, which they've been using from the start, is going to dominate such applications. Besides, the chirping is going to get drowned out by Geiger-counter clicks and the sound of relays snapping open and closed.

    If something is important enough to be allowed into the control room, then its too important to have such basic causes of failure.

    1. vir

      As someone who has spent a bit of time in a plant control room, I will say that the meters do not make a clicking sound and that any relays close enough to be audible aren't operating that frequently; the biggest source of noise is the air handling.

      Agreed that if something is important enough to be needed in the control room, it's probably important enough to plug in, though.

  4. toxicdragon

    Jesus christ, yeah the talking paper thing is kind of impressive but did they have to use stupid slang and that "just for you" bit? Advertising might be basically whoring out a product but that is just irritating.

  5. Ammaross Danan

    The audio equivalent of a QR code. Modem-style.

  6. vir

    We All Know Where This Is Going

    "What Chirp has developed, essentially, is a protocol that allows every unconnected device to talk to a network,” said Lerner.

    "What Chirp has developed, essentially, is a protocol that allows every unconnected device to display targeted advertising,” said Lerner.

    FTFY.

  7. Mage Silver badge

    licensing the technology

    How absolutely trivial and basic. There is NOTHING about this worth licensing.

    It doesn't seem very well thought out or secure either.

    It's practically a scam.

    1. John Tserkezis

      Re: licensing the technology

      "It's practically a scam."

      I was going to say its first use would be DRM, but you effectively beat me to the punch...

  8. phillr

    The hacking potential is enormous. Imagine what's going on with the attack against Phillips Hue light bulbs, but using Chirp audio data transmission. Imagine spying on all those audible data transmissions.

    Thanks, but no thanks.

    1. Daniel Jones (Chief Science Officer, Chirp)

      There's a useful analogy in thinking about Chirp in the same way that TCP/IP is to networking. On its own, TCP/IP does not offer any native security features, and is susceptible to sniffing, MITM attacks, etc. However, secure transport (https, ssh) can then be introduced on top of it, which provide true end-to-end security - an attacker that captures the raw IP stream simply obtains meaningless data.

      Exactly the same applies to Chirp: we don't provide security innately, but we offer a transport layer that happily supports industry-standard crypto algorithms, so it's straightforward to create a secure dialogue that still takes place in the audio band.

      We've trialled two-way secure comms successfully with PKI-based approaches. There's also the option of approaches such as time-based one-time passwords (TOTP) for lightweight and secure token-based auth.

      1. jake Silver badge

        Interesting.

        So do I need to flip a switch for "talk" or "receive" like I do on my Bell 202?

  9. Zot

    Did I say I wanted...

    ...R2 fucking D2!?

  10. d3vy

    So it MODulates a digital signal into analogue and then transmits it to another device which DEModulates it from analogue to digital.

    I'm sure ive heard of something similar... :)

    1. Charles 9

      Except in this case there's no need for an acoustic coupler like in the old days. It's good enough to operate through the air and at short distances in contrast to over phone lines.

      1. VinceH
        Coat

        True - but it's also a bit limited in terms of the amount of data that can be transmitted.

        However, with some improvement, it could be possible to carry quite a bit more data.

        Then it could be useful to transmit that data over telephone lines, using the MODulation/DEModulation approach d3vy suggests.

        It could also be stored on an external medium - such as audio cassette, for example, which we can load into the device by playing it back. I expect it'll make an awful noise when it carries a lot of data, though, so it'll probably be sensible to connect it using a short lead going from the headphone socket of the cassette deck.

        The future looks really cool!

      2. Loud Speaker

        Actually, judging by the annoying nature of the communications, I'd say there is a strong need for an acoustic coupler - which was basically a foam filled wooden box to keep the bloody noise in.

        As for sending data as audio - I think that was standard practice in the 1880's - it certainly pre-dates Morse and his code. And RTTY is a lot better at sending asynchronous ASCII.

  11. John Smith 19 Gold badge
    Unhappy

    Thought it was going to be very clever. Like spread spectrum in sound

    Which is what a US toy company came up with in the 80s IIRC (Pop. Sci article?)

    But this is audible. And SS data rate with a sound carrier is about 2-3 bits per second.

    That said the clever part is probably a)Code selection for maximum detection in high ambient noise environments and b)Filter algorithms to detect that code efficiently .

    The idea is pretty obvious.

    I suspect the implementation less so.

  12. John H Woods Silver badge

    Not new...

    I buy cheap IPcams to monitor horses and rural locations --- many of them use an Android app to configure. Typically these can both scan QR codes on the cameras for setup AND transmit Wifi details from the phone to the cameras (which have microphones) by what certainly sounds like an audible chirp.

  13. Mike 16

    Standards

    And yet, they chose to not follow RFC 1926. "so many to choose from"...

    1. Diginerd

      Re: Standards

      Wow, how did I miss RFC1926? - it's a corker! Upvoted ;-)

      Isn't it ironic (Don'tcha think?) - RFC1926 comes right after RFC1925...

      For those reading this with a frown and a healthy dose of "WTF they talking about?"

      RFC1925 is the first of the "Desert Island RFCs" ("DIR'). It SHOULD be manadory reading for everyone working in technology & failure to grok it is a common problem of startups...

      Click bait (Fair warning - the rabbit hole is deep!) https://tools.ietf.org/html/rfc1925

      Of course, the second DIR MUST be RFC1149 ;-)

      Akin to Rule34, and verifying RFC1925, OP linked RFC1926. Nicely done sir!

      Cheers!

      WRB - IOOF

  14. Frumious Bandersnatch

    the audio bursts are [...] one-to-many

    This could be quite useful as an out-of-band signalling method. The article goes on to say that it could be used as a broadcast medium in something like a stadium. I think that this sort of oob channel could also be useful as an adjunct to a reliable multicast system. The problem with many multicast algorithms is that explicit ACK/NAK packets get progressively worse the more listening stations you add, to the point that they consume the bandwidth required by the broadcaster, making the whole thing less efficient.

    To quote Leonard Cohen: "The fourth, the fifth / The minor fall, the major lift / The baffled king composing Hallelujah"

    Assume that we have a modulation scheme to signify explicit ACK/NAK using a particular "chord", and a Bluetooth-like (base) frequency hopping algorithm to encode frame numbers, then providing the receiving stations have enough power to pump out their ACK/NAK packets, then the broadcasting station can listen to a wide spectrum of audio input and use FFT plus some sort of convolution (?) algorithm to detect specific chords at any base frequency. As a first pass, this should be able to figure out the actual error rate (by listening to the loudness of the NAK chord signature across all frequencies), and with more processing it could identify particular packets/frames that need to be retransmitted.

    Still with the stadium example, you could imagine shrinking the technology down so that each phone could act as a transceiver, with a quorum-sensing algorithm quenching explicit OOB signalling in a localised area (with a hard cut-off to effectively become deaf to all the other nearby chirps outside a certain radius) along with lower-bandwidth retransmission of lost packets and possibly directionality so that those at the back can find out just how blessed the cheesemakers are.

    (I'll bid you farewell. Don't know I'll be back---they're moving me tomorrow to the tower down the track ...)

  15. jake Silver badge

    One wonders what happens ...

    ... if one rattles one's keys at it ...

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