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According to the article, "can" = has the capability to. Isn't that obvious though? Any internet connected device with a microphone has the capability to alway

• woodrowbarlow 9y ago
  according to security principles, "can" = we must assume that it will or has been, given the proper motivation. the iphone has a low-power asic whose sole purpose is to listen for "hey siri" with relaxed confidence intervals. the real voice processing isn't done until the main cpu is woken by this asic. because of this, we can identify discrete modes of operation in the iphone, one of which is incapable of doing arbitrary "spying". based on the article, it sounds like the alexa doesn't have this affordance. while unsurprising in this case, i don't think we must accept that anything with an internet-connected microphone has the capability to always listen to what you say.
  • paxy 9y ago
    Alexa and all other "always-listening" devices do have the standard on-chip processing mechanism. The article is about how the trigger can be expanded from a single word to a broader range of sounds.
  • deleted 9y ago
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  • DSMan195276 9y ago
    I'm not sure the distinction is as notable as you're making it. The iPhone as you describe it is perfectly capable of listening to everything you say, it just has to never release control of the mic to the low-power ASIC. I'm also not sure the article actually indicates what you're saying, it's kind-of vague. For example, it never states that anybody was able to actually program Alexa with a new wake-word, just the possibility of being able to create different signatures that could be used as wake-words. And the description of how they prevent things like the superbowl ad could all be done after Alexa detects the wake-word wakes up the main processor, but before Alexa actually responds to the user. I don't see anything in the article that indicates Alexa can't be using a separate chip dedicated to listening to the wake-word. To that end, not to long ago a Reddit user claimed that Alexa did have two separate modes it operated in [0]. Which, it is entirely possible they could be lying, but you could always just open the thing up and take a look. But even if it does have a separate chip my previous point about the iPhone still applies, so besides power-usage I don't think it is extremely notable. [0] https://np.reddit.com/r/Showerthoughts/comments/7m91u9/if_google_devices_only_start_listening_once_you/drsdxe1/?sh=c90d0649&st=JBO70BSD https://np.reddit.com/r/Showerthoughts/comments/7m91u9/if_go...
    • secabeen 9y ago
      The other angle is that were Alexa actually recording and sending voice data frequently, it would show up in the traffic data. Unless they're smuggling past recordings along piecemeal along with actual recordings, traffic analysis would work.
      • Klathmon 9y ago
        Unless they are capable of doing the speech-to-text on-device, then the amount of data is negligible. Hell, if they were really crafty they could have it listen for a specific phrase or word, then send back as little as a single byte signifying that it was heard. (I own an echo and a few Google homes, and I don't actually think this is happening, but the idea is kind of fun to chase)
        • sitkack 9y ago
          > Unless they are capable of doing the speech-to-text on-device, then the amount of data is negligible. What is the lowest bitrate codec and how does it compare to the plaintext version?
          • Klathmon 9y ago
            Well considering text is literally hundreds of bytes, I can't imagine audio would be able to keep up.
            • sitkack 9y ago
              Take a look at the BoE calc that someone else did in this thread, it might shed some light on what is possible.
          • deleted 9y ago
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        • secabeen 9y ago
          Yeah, that is an interesting idea. I'm not sure anyone is making an ASIC for speech-to-text right now, but if they were, it could enable this sort of thing. Might show up in a teardown, though. A General Purpise CPU could of course, do it, but that would push the bill of materials for the device up quite a bit.
  • erichurkman 9y ago
    iPhone vs. Alexa, HomePod, Google Home: phones are often on battery power. They need a low-power mode for listening otherwise it will kill user batteries. A device plugged into an outlet? No incentive for power saving.
    • paxy 9y ago
      Even Amazon, with all the server capacity in the world, is not going to be able to store and process every sound heard by every Alexa in real time.
      • throwaway2048 9y ago
        no, but its entirely feasable to store all spoken word transcripts.
      • pdkl95 9y ago
        > is not going to be able to store Voice codecs like AMR[1] (or GSM-HR) only need 2-3MB/hr. A trivial noise gate[2] that cuts out silence should allow a recording duty cycle under ~1%. Amazon can easily store all the voice recording they want. > and process ... in real time Processing isn't that expensive once you have a trained classifier. However, realtime processing often isn't necessary. [1] https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_codec https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_audio_code... [2] https://en.wikipedia.org/wiki/Noise_gate https://en.wikipedia.org/wiki/Noise_gate
        • rootw0rm 9y ago
          Excellent response.
        • zeta0134 9y ago
          I don't doubt that what you say is correct, but I think the author's point is that even with those optimizations, the sheer amount of data from [Every Alexa in the world] * [Every second of every day] is too much for any remote service to process. The wake word needs to be handled locally so that the remote service is only involved when needed. The amount of data for a single recording can be quite small, but multiplied by a large population it still adds up in a hurry.
  • squeaky-clean 9y ago
    since Siri is mostly processed remotely ("in the cloud") you can test this by trying Hey Siri in airplane mode. It will hear it's name but can't act any further.
• mlazos 9y ago
  At least for me the reason I’m fine with my phone is that it’s a metered connection. If it was sending that much data to the mothership you’d probably hit the ceiling on your data plan really quickly. Since my home connection doesn’t have such a ceiling it’s a bit scarier.
  • ryanplant-au 9y ago
    Not necessarily, there are lots of phone service providers who except certain websites or services from the data tracking. Some of them Google services already -- Virgin Mobile in Australia excepted YouTube traffic for years.
  • dev_throw 9y ago
    Yes, it is a metered connection, but unless you implement the metering, you don't know how much data you're leaking. For example, in some plans, Netflix data is not counted towards the plan.
  • justin66 9y ago
    With decent audio compression you're talking something like 50 or 60 megabytes per hour of audio (half that in mono, come to think of it). Assuming your listener software is doing a little work to not send silence or unintelligible noise, I bet the data usage would be totally dwarfed by regular use of the phone.
    • baobrien 9y ago
      With a low bitrate speech codec, you can get well down to 1 or 2 megabytes per hour.
    • uptown 9y ago
      Why would it need to send audio? Convert it to text in the device and send that.
      • justin66 9y ago
        You're right, but most of the real intelligence in the voice-to-text these devices are relying on comes from computation done on the server side, I believe. That way they get to constantly train the algorithm with new data, and so on and so forth. (the point still stands, either way: the network bandwidth these things use is not a big deal)
• hoosieree 9y ago
  Your most solid guarantee that your device isn't constantly spying on you is a battery. Listening for words is power-intensive.
  • mikeash 9y ago
    Recording at a low (but still intelligible) bitrate and uploading it when connected to power would be pretty easy on the battery.
    • kbenson 9y ago
      I'm not familiar with the current state of the art in speech recognition, is there a low bitrate which is still intelligible to speech recognition engines, or is this still a domain that the human brain has enough of an advantage?
      • ryanplant-au 9y ago
        What do you consider to be low? Anecdotally, the Google app on my phone almost perfectly recognised, played over speakers, this fairly rapid dialogue between two people encoded as 6 Kbit/sec Opus. https://ryanplant.net/love.wav https://ryanplant.net/love.wav Its only mistake was missing the "you" in "you want to be." Codec2 remains fairly clear down to human ears down to 2.4 Kbit/sec but I had no luck getting it recognised, even with much simpler and clearer samples. This individual anecdote tells you nothing about the state of the art, but I wanted to note it anyway because I was astonished at how well 6 Kbit/sec is handled.
        • oneweekwonder 9y ago
          I'm aware I don't know what I'm talking about. But the love.wav gives a bit rate of 768kbps, 6 sec of audio at 571 KB storage size. Another poster also did the math on 5.6 kbit/s (700 bytes/s). > 5.6 * 60 * 60 / 1024 / 8 = 2.4609375 MB/hr But should that 5.6 not be 768 to get love.wav voice quality? What am I missing like a moron? Thanks for the example and anecdote, something to actually grasp in trying to understand the problem.
• jsoc815 9y ago
  > Isn't that obvious though? You'd think so, but no. I tried to explain this to some co-worker back when the Samsung TV issue came out. They didn't understand and literally made me out to be some conspiracy theorist. Their thinking is/was 'Why would X be listening to me if I didn't press the button or say the special word?' Same deal w/the cellphones. I've stopped trying to explain.