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Why Alexa Won't Light Up During Amazon's Super Bowl Ad (bloomberg.com) 80

Bloomberg: Amazon.com is advertising its Alexa-powered speakers in the big game on Sunday. It's an amusing 90 seconds that features celebrities like Gordon Ramsay, Rebel Wilson, Anthony Hopkins, Cardi B and the world's wealthiest man, Jeff Bezos himself. The word "Alexa" is uttered 10 times during the Super Bowl spot, but thankfully, the Amazon Echo in your living room isn't going to perk up and try to respond.

Bezos and company have evidently been thinking about this problem for a long time, before the Echo was even introduced. A September 2014 Amazon patent titled "Audible command filtering" describes techniques to prevent Alexa from waking up "as part of a broadcast watched by a large population (such as during a popular sporting event)," annoying customers and overloading Amazon's servers with millions of simultaneous requests. The patent broadly describes two techniques. The first calls for transmitting a snippet of a commercial to Echo devices before it airs. Then the Echo can compare live commands to the acoustic fingerprint of the snippet to determine whether the commands are authentic. The second tactic describes how a commercial itself could transmit an inaudible acoustic signal to tell Alexa to ignore its wake word.

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Why Alexa Won't Light Up During Amazon's Super Bowl Ad

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  • by Anonymous Coward on Friday February 02, 2018 @04:54PM (#56057985)

    The second tactic describes how a commercial itself could transmit an inaudible acoustic signal to tell Alexa to ignore its wake word.

    So either they're assuming the device will be able to produce the required frequency, or my dog will go nuts. God help us.

    • There is a similar process on CISCO Teleconference screens. Apparently its IP Address is sent in High Frequency so if you had some software on your device you can share your screen without having to plug it in. However it doesn't work if your device isn't in the same room. (or not connected to the network)

    • That's actually a really good point... and one that I was going to mention myself. Does anybody know what the upper cap is on frequencies that can be produced by modern audio equipment? I'm betting that if they can even produce inaudible frequencies at all, it's not liable to be much higher than the maximum human hearing frequency, and that would still be well within the hearing range of many household pets, so I think we'd need to investigate that carefully before filling people's homes with it. If they
      • by EvilSS ( 557649 ) on Friday February 02, 2018 @05:32PM (#56058335)
        It doesn't need to be an inaudible frequency, it just needs to be hidden from human ears but distinguishable for machines. Nielsen's system (Psychoacoustic encoding) uses audible sounds hidden under the regular broadcast audio (and this is why they don't encode during silent segments of audio in shows or commercials).
      • The upper limit for FM used in television broadcasting is 15 KHz.
      • That's actually a really good point... and one that I was going to mention myself. Does anybody know what the upper cap is on frequencies that can be produced by modern audio equipment?

        This depends on many factors. Home equipment can certainly produce a frequency above 20kHz. For example the Marantz PM5005 is specified to achieve a frequency response up to 50kHz. Most high quality tweeters are capable of going well above 20kHz. Of course, not everyone has good equipment or speakers and there will be rolloff. In addition all of the signal processing and compression of the transmission likely has digital filters knocking out much of the out-of-band data. Practically I'd expect somewhe

        • Most broadcast is either done over the air or cable (or converted to a similar signal) using rather old encoding techniques. I'd have to look it up but I think the high end is 15kHz. The "HD" channels are generally 720p or 1080i, I have not yet seen a 1080p30/60 cable/sat provider when they require use of a set top box.

          If you still have grandparents, they often still have cable and you can hear how muffled and low quality a tv show sounds/looks if you're used to seeing it mastered for digital in places like

      • by mysidia ( 191772 )

        I'm betting that if they can even produce inaudible frequencies at all

        How about coded white noise at the same volume as "Alexa" of a duration imperceptible to humans?

        This is similar to the idea of steganography...... hiding a more complicated message inside a picture or sound file
        by applying variations that human eyes or ears won't detect.

      • I am a software engineer rather than an audio hardware engineer, but working alongside such engineers and developing software for tuning audio equipment I know a little bit about what they're doing. As I understand it, our products handle frequencies a little bit under 20Hz and a little bit past 20kHz - essentially a band pass is in place on the input to prevent anything higher infrequency which can damage the set (there may be additional filters, we have a digital signal processor for example that lets you
    • by sremick ( 91371 )

      I can't wait until someone figures out the signal and invents an Alexa-jammer/DOS emitter device/app.

    • by EvilSS ( 557649 ) on Friday February 02, 2018 @05:28PM (#56058301)
      Nielsen uses audio signals hidden in broadcasts every 2.5 seconds for their tracking, so I don't see Amazon having issues doing something similar.
    • So, if you put something in the room generating noise between 3,000 and 6,000 Hz (to fill in the gap in the commercial's audio), an Echo might respond to everything in the commercials?

      Could be a fun experiment.

    • This could get interesting. Just wait till commercials start sending Alexa commands in an inaudible acoustic signal to buy items from Amazon, or start playing their latest hit, or even just turn out the lights. Maybe it's happening already...

      • by mysidia ( 191772 )

        How about this: Amazon will sell a service where Alexa will listen for certain inaudible acoustic commands, which you can embed a unique ID into your Broadcast, or Radio program, or insert into your song, and Amazon will provide you intelligence or data about how many people and what demographics are listening to your content.

        • by Kjella ( 173770 )

          How about this: Amazon will sell a service where Alexa will listen for certain inaudible acoustic commands, which you can embed a unique ID into your Broadcast, or Radio program, or insert into your song, and Amazon will provide you intelligence or data about how many people and what demographics are listening to your content.

          That's... actually not that unlikely an idea, like a service-neutral super-Nielsen rating. The microphone is listening anyway, all it takes is a different trigger signal to say "I'm content {7c76a643-711e-4b5e-af72-f40a77ca0075}", along with a timestamp you could buffer up tons of these in a few kb and flush when the device is talking to the network anyway. You'd probably need some kind of consent but that's one EULA change away. I'm sure it can be justified with some "enhancing the customer experience" flu

    • The CODEC is another potential snag. Lossy algorithms like MP3 make a POINT of mangling and filtering away things that are "inaudible", especially if there are lots of OTHER things going on in the audio at that instant.

      I'm not sure about AC3 & Dolby Digital, but I know that MP3 absolutely DESTROYS phase relationships used by algorithms like Qsound (for a very audible example, find a CD of Madonna: The Immaculate Collection, rip it, compress it to MP3 at 384kbps, 256kbps, 128kbps, and 64kbps (all CBR, no

  • The second tactic describes how a commercial itself could transmit an inaudible acoustic signal to tell Alexa to ignore its wake word.

    Step 1: A dedicated, battery operated, highly miniature device to emit said signal
    Step 2: ??? Alexa remains silent...
    Step 3: Profit!

    • Remember TV-B-Gone [tvbegone.com]? Build a similar device that uses ultrasound to turn off Alexa and similar devices.
      Bonus points: Has more than one button, other buttons produce rogue Alexa requests/commands, but in the ultrasound range, so no one knows how or why Alexa is doing what it's doing.
      More bonus points: make the 'rogue command' feature user-recordable (i.e. pitch-bends your voice up to the ultrasound range).
  • If someone has one of these spy devices in their home they deserve all the worst the world has to offer.
    • Yes, but this isn't about the end-user and the device in their home. This is about not clobbering Amazon's servers.
  • by PFactor ( 135319 ) on Friday February 02, 2018 @05:13PM (#56058183) Journal

    transmit an inaudible acoustic signal to [..] Alexa

    But we promise we're not using this to send a tiny packet indicating you were exposed to a given advertisement, so we can send that to advertisers for money.

    ...Why are you laughing? We can tell because you paid for an always-on, internet-connected microphone in your home.

    • by tlhIngan ( 30335 )

      Better yet, remember the whole Burger King What is a Whopper thing?

      It sounds like a perfect opportunity to continue your ad for another 30 seconds, crap on the next guy's ad, and save yourself $5M by taking only 1 30 second ad spot instead of 2.

      I'm wondering how many times ads will intentionally trigger Alexa/Google/Siri during these times. Hell, maybe you can get them all to dial 911 at the same time and do a massive DDoS of the emergency system.

    • This Kickstarter project for 'Mycroft Mark II: The Open Voice Assistant' is trying to be the open and privacy safe version of the Echo: https://www.kickstarter.com/pr... [kickstarter.com]
    • by Anonymous Coward

      ...Why are you laughing? We can tell because you paid for an always-on, internet-connected microphone in your home.

      As opposed to the (potentially) always-on, internet-connected microphone in your pocket, which for some reason is magically acceptable.

  • south park messed up lot's of alexa's with there stunt

  • If Alexa responded to commercials and randomly awarded a year of free Amazon Prime to the viewer.

  • Surely the super duper AI in Alexa can tell if the command is from a TV, or from someone in the room? Even a two year old can do that!!!
  • Tactic #3 and #4: (Score:5, Insightful)

    by Rick Schumann ( 4662797 ) on Friday February 02, 2018 @05:34PM (#56058355) Journal
    #3: Leave it unplugged from power unless you're actively using it
    #4: Don't buy the goddamned thing in the first place (preferred solution)
  • The patent broadly describes two techniques. The first calls for transmitting a snippet of a commercial to Echo devices before it airs. Then the Echo can compare live commands to the acoustic fingerprint of the snippet to determine whether the commands are authentic. The second tactic describes how a commercial itself could transmit an inaudible acoustic signal to tell Alexa to ignore its wake word.

    'Acoustic fingerprint' comparison is used all the time to search sites like Youtube for rights violations. And transmitting an audible signal to tell an electronic device to do or not do something has been around for decades. So these examples of prior art are suddenly new and patentable 'because Alexa'? Gimme a break! Can there be any better indication of how thoroughly the patent system is broken?

    • They're not patenting either technology. They're patenting using them to prevent a smart speaker from responding. It's the difference (in law at least) between patenting "eating plants" and "eating XYZ to cure cancer"

  • Amateur radio and commercial radio systems have been using something like this for many decades, except it is the opposite. Only when a sub-audible tone (or more specifically, a tone that is not within the normal filtered audio output range of the radio) of a specific frequency is received will the radio "recognize" the signal and open the squelch so the audio can be heard. This is reverse CTCSS, where the tone must not be present for the audio to be processed. They can also use such a tone to "mute" Alex

    • not within the normal filtered audio output range of the radio

      I have people telling me all the time that something is wrong with my repeater because they're hearing a hum on the output. It's the PL tone (screw Motorola, I'm using their trademark anyway.)

  • by green1 ( 322787 ) on Friday February 02, 2018 @05:59PM (#56058563)

    The problem isn't that a specific ad can trigger this thing, the problem is that ANYBODY can trigger this thing.

    If they actually cared about privacy, security, or the end users, they'd work hard on voiceprinting technologies so that it only responds to it's owner and nobody else. That would simultaneously solve this problem, as well as that of other malicious advertisers, and that of random drunk friend thinking it's funny to order hundreds of things with it.

    Not that I think voiceprints are particularly secure or reliable, but it's infinitely more secure than what they have now.

    • Alexa can already differentiate between different voices:

      https://www.theverge.com/circu... [theverge.com]

      There could very well be some upcoming feature that limits certain commands to certain voices (and is user-defined). There have been a lot of features added in the last year.

      Generally, though, there aren't many people in my house that aren't my family and friends, so I'm not too worried.

      • by green1 ( 322787 )

        So if this is truly the case, why would they need the features listed in the article?

        Either it only listens to the right voices, and therefore the features aren't needed, or it doesn't, in which case the features in the article are addressing the wrong problem.

    • The problem isn't that a specific ad can trigger this thing, the problem is that ANYBODY can trigger this thing.

      If they actually cared about privacy, security, or the end users, they'd work hard on voiceprinting technologies so that it only responds to it's owner and nobody else.

      They already do, and sensitive information is only revealed to the person identified. Unless you think there's some innate security concern with your friend coming over and asking your Alexa what the weather is outside.

      • by green1 ( 322787 )

        So if they already do, then the method stated in the original article is 100% pointless. right?

  • Just today, listening to a news broadcast and the announcer said "time" and Alexa gave me the time. Nothing remotely like the activation work preceeded it. Meanwhile, I get to the store and my Alexa generated grocery list is a jumble of misheard items I must decipher. I just checked right now and I have "grape ground beef", "risotto martin final", "risotto smart and final" and my favorite "masker pone un trader joe's you idiot"
  • Of these things in my house. They are always on, always listening. Television can broadcast something like a "audio QR" code that humans probably won't hear, or, can't understand, but the little speaker/microphone thingy can. No, not paranoid, just don't want something like that in my home.
  • Previously, when Alexa heard its name on an ad, it would briefly light up, but would then (presumably by sending audio back to the mothership and having it rejected) shut down again.

    Now, they've started fudging with the audio, so instead of saying "Alexa" it sounds like "Alekfa" and doesn't trigger it at all.

  • Had I only read the summary, I would have been left believing that the only reason anyone thinks Amazon is actually doing this is because someone was trolling through Amazon patents and concluded that because they got a patent on an idea they must be practicing it. Here's the real meat of TFA:

    About a year ago, a Reddit user calling himself Asphyhackr did a little more legwork and concluded that Amazon was creatively employing this second technique. By running Alexa commercials through digital audio editing software, Asphyhackr discovered that Alexa ads transmit weakened levels of sound in an upper portion of the audio spectrum, between 3,000 and 6,000 hertz, outside the most sensitive range of human hearing.

    Asphyhackr speculated that Amazon could be tipping Alexa off to ignore certain commands if it detects artificial gaps or bumps in the spectrum. To test his theory, he recorded someone saying “Alexa” and used a so-called band-stop filter that reduced frequencies just in this high region of the spectrum. When he played back the recording, “My echo would not wake, even sitting right next to the speakers!” he wrote.

    Amazon just blogged about this topic and shed perhaps a bit more light on it. The company credited "acoustic fingerprinting technology that can distinguish between the ad and actual customer utterances" and said that its advertising, engineering and science teams prepare for major events like the Super Bowl commercial, in order to suppress Alexa devices from responding to it. When a major broadcast of the wake word "Alexa" is unanticipated -- for example, when it’s mentioned on the “Tonight Show” -- Amazon said its cloud servers can detect a match, create an audio fingerprint on the fly and can prevent 80 to 90 percent of devices from responding.

    • Sweet. So assuming that they continue this avenue and create a host of commands they can transmit to everyone's home secretary via shows and songs, what sort of tools are going to be available for me to send out while I'm visiting that abnoxious friend with one of these things?

      I mean, of course I can have my smartphone play this "ALEXA OFF" command on repeat and that'll save me from having to watch him, yet again, try and show off his latest toy. But there's bound to be other commands, right?

  • I suddenly wish I was a very popular streamer on twitch or youtube. I would record this 'inaudible acoustic signal' and isolate it using trial and error, and just play it back continuously throughout my stream.

  • Will Echo call home to tell Amazon you watched the add?

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