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Sonar Software Detects Laptop User Presence

Steve Tarzia writes "A research group at Northwestern University and University of Michigan has released open-source display power-management software that uses a new user presence detection technique. The goal is to shut off the display immediately when the user leaves the computer rather than using slow and error-prone mouse/keyboard activity timeouts. Surprisingly, the mic and speakers of many laptop computers are sensitive to ultrasonic frequencies. Those frequencies can be used to silently probe the laptop's physical environment. This software is based on research published at the UbiComp2009 conference. A Windows binary and source code for Windows and Linux are available for download."

41 of 167 comments (clear)

  1. Safe? by DoofusOfDeath · · Score: 2, Funny

    Damn, now PETA is going to bitch about what happens when dolphins use these laptops.

    1. Re:Safe? by El+Torico · · Score: 5, Funny

      "We can't use that laptop here, this is bat country!"

      --
      In the land of the blind, the one-eyed man is usually crucified.
  2. Takes Care of one of my pet peeves by gpronger · · Score: 3, Interesting

    Don't know if I type slow, think slow, or both, but one of my pet annoyances is when the screen saver kicks-in as I'm staring at the screen in thought (sure I know how to set it, but I am not always in front of my own PC, and oft away and then back a lot through the day).

    If this will simply tell the OS, hold on, he's sitting there doing something, I'd find it a pretty neat idea.

    Greg

    1. Re:Takes Care of one of my pet peeves by spun · · Score: 5, Funny

      I, too, often find myself looking at a screen for extended periods of time without touching the mouse or keyboard, while I, ah... read the articles. Nothing ruins a good article more than having the screen saver start up right as you are about to finish.

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    2. Re:Takes Care of one of my pet peeves by schon · · Score: 4, Interesting

      Something like this has been available for KDE for ages, only it uses Bluetooth.

      You tell it to listen for your phone - when you leave your desk (presumably with the phone in your pocket/holster/etc.) the screen lock kicks in.

    3. Re:Takes Care of one of my pet peeves by Anonymous Coward · · Score: 2, Informative

      Don't time your screensaver so aggressively. Turning the screen off after just a few minutes is useless and just puts unnecessary strain on the backlight (which takes only a limited number of power cycles, unless it is LED).

      I use Ampsoft's Screen Saver Control to manually put the screen into power saving mode with Win+P (and the standard Win+L to lock the screen, if I think that's necessary). I have set the power saving mode to kick in after 2 hours of inactivity otherwise.

    4. Re:Takes Care of one of my pet peeves by jmerlin · · Score: 2, Funny

      You actually read the articles?

    5. Re:Takes Care of one of my pet peeves by Arthur+Grumbine · · Score: 2, Funny

      That whooshing sound you hear is not your laptop's sonar.

      --
      Now that I think about it, I'm pretty sure everything I just said is completely wrong.
    6. Re:Takes Care of one of my pet peeves by amicusNYCL · · Score: 3, Funny

      I, too, often find myself looking at a screen for extended periods of time without touching the mouse or keyboard, while I, ah... read the articles. Nothing ruins a good article more than having the screen saver start up right as you are about to finish.

      That's funny, the exact same thing happens to me when I'm watching porn.

      --
      "Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
    7. Re:Takes Care of one of my pet peeves by spun · · Score: 3, Funny

      My God. There's porn on the Internet now?

      --
      - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    8. Re:Takes Care of one of my pet peeves by dlgeek · · Score: 2, Interesting

      Yes, I know this was intended as a humorous remark, and yes I get the joke (please refrain from any "woosh" comments), but in all seriousness, this actually is an issue for X11 based systems.

      Due to a poor design choice in X11, applications can see when the mouse moves but can not see button press events in other applications. One result of this is that screensavers can't detect a mouse wheel. Thus, if you're scrolling through a long article, the mouse wheel events aren't seen, the screensaver considers you idle, and will lock the screen even as you're scrolling.

      It's actually quite annoying...

  3. I'm still here! by John+Hasler · · Score: 3, Funny

    I'm just asleep, you insensitive clod! (or does it detect snoring?)

    --
    Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
  4. I wonder how... by Whorhay · · Score: 3, Interesting

    I wonder how fine of a resolution is possible with a setup like this with generic microphones and speakers. Maybe it would be possible to use this as a biometric lock on a computer system. It could function as a facial recognition check using the ultrasound picture or series of pictures of your face. Lighting wouldn't affect it and someone couldn't simply use a picture of you to try and fool the camera. Even a bust of your face wouldn't work the same unless it accurately simulated your bone structure and flesh.

    1. Re:I wonder how... by maxfresh · · Score: 3, Interesting

      I agree that a webcam would do a far better job than speakers and mic, but they couldn't use body heat to do it.

      Although a ccd or cmos sensor in a webcam, or most any other digicam, is sensitive to IR as you mention, it is not sensitive to the thermal IR of body heat. Most digital cams are capable of IR sensitivity out to about 1um, if you remove their IR-cut filter. The human body with a skin surface temp of about 305 Kelvin emits most of its IR energy at a wavelength about 10x longer than this, or 9.5um.

    2. Re:I wonder how... by Z34107 · · Score: 2, Interesting

      Asus ships the software you're describing with laptops they sell; it came on mine. It takes a bunch of snapshots of your face through the webcam (you're supposed to rotate your head) and then if it sees your face at the login screen, it logs you in.

      They call it "SmartLogon."

      --
      DATABASE WOW WOW
    3. Re:I wonder how... by tkw954 · · Score: 4, Insightful

      Asus ships the software you're describing with laptops they sell; it came on mine. It takes a bunch of snapshots of your face through the webcam (you're supposed to rotate your head) and then if it sees your face at the login screen, it logs you in.

      So all I need to log on to your computer is a lifesize photo of you, or alternately, your severed head?

  5. Re:Activity by lordandmaker · · Score: 4, Insightful

    Mouse/keyboard activity timeout works nicely for that.

    I find it doesn't. My PC at work has to be configured to require a password be entered on exiting the screensaver, and my password has to be quite complex. If I'm working on something that's not the PC (yeah, we still use paper for things) for longer than the minute, I've got to enter my password to carry on, which is irritating.
    It's less irritating when it kicks in when I'm reading or watching a video or something, but I'd still prefer it not to, and I really don't see the privacy angle on this. It's no idea where I am, just that there's something in front of it.

    But, generally, I don't have much of a problem with my computer knowing all sorts of stuff about me, it's what it tells to who that I concern myself with.

  6. Headphones by quantumphaze · · Score: 3, Insightful

    This wouldn't work with headphones plugged into the computer unless you can get the laptop's built in speakers working independantly (it can do it, old Ubuntu 7.10 had them on separate mixer controls on my laptop). But desktop users usually have their powered speakers off when using headphones.

    Does anyone have an idea on how to solve that? You could put out ultrasonic sound through the headphones that get blocked when used, but it could damage your hearing depending on how loud it needs to be to get picked up by the microphone.

    1. Re:Headphones by sakdoctor · · Score: 5, Funny

      The solution to this, and ALL life's problems is to uninstall pulse audio.

    2. Re:Headphones by CAIMLAS · · Score: 2, Interesting

      That.

      Personally, I went back to just using ALSA + internal alsa mixer. That kinda sucked (couldn't get it to consistently mix, particularly with Flash, and it would frequently result in poor quality crap while doing so), so...

      I went back to what I was doing a decade ago: use ESD (wherever possible). I suppose I could use JACK or something else, but it does a good enough job and I'm not continually irritated with alsa dying outright due to different things vying for -whatever-.

      --
      ~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
  7. Re:Activity by Chris+Burke · · Score: 2, Informative

    Mouse/keyboard activity timeout works nicely for that.

    Er not really. You need to set it to long enough that it doesn't time out every time you read a page of text (unless you just like idly dragging the mouse around while reading... i don't). Yet you want it short enough that it provides power savings. The LCD screen is a big power hog in a laptop. Being able to turn it off instantly as soon as you walk away, and turn back on when you sit back down, would be the best of both worlds of power savings and convenience.

    I rather don't have the computer know if I'm walking near it or not. But it seems we're heading in to this "everyone, and every machine, knows where you are" every day.

    Yeah I'd be more worried about the fact that your computer knows every single thing you type, and every single thing you read. ZOMG!

    But seriously. It knows whether you are in front of your laptop or not. Are you often running your laptop when you aren't around at all, such that the assumption that your laptop being on and connected to the network is generally accurate? Like it's a big danger that the laptop knows you aren't there anymore when you get up for a quick piss break. Not that it knows you went to the bathroom!

    Besides, it's open source. If you're that worried that it's going to report your location to The Man, check the source code.

    And hey, if you're really worried about realistic ways for The Man to find you, take the battery out of your cellphone. Seriously, that's a real way in which the phone company/police can locate you.

    --

    The enemies of Democracy are
  8. I'm one of those people that hears CRT Monitors by ArbitraryDescriptor · · Score: 4, Interesting

    And dimmer switches, cordless drill battery charges, and even a really annoying slice of whatever frequency god damn bats chatter at. In short, my super power is above average HF hearing. Hooray for me...

    Now, I like this idea, it's neat, I just really hope it operates well over 18khz so my head does not explode all Scanners style when I walk into a room full of laptops.

    1. Re:I'm one of those people that hears CRT Monitors by marcansoft · · Score: 2, Informative

      Dimmer switches buzz at 50/60Hz (with lots of metallic-sounding harmonics). Everyone hears those. Better designed ones make less noise. Battery chargers and power adapters in general (of any kind) either buzz at 50/60Hz (transformer based) or at a higher frequency (switching type). Poorly designed switching converters might operate in the audible range - I have a few that can definitely be heard. Most good ones are well above 20Khz. CRT TVs operate at ~15Khz; I hear those too. CRT monitors operate well above 20Khz; ~30Khz for 640x480 VGA (horizontal frequency). I doubt you can hear those. Maybe some specific monitor that produces noise at a division of the frequency?

      I tried this on my laptop and I couldn't hear anything (other than some clicks when it is enabled/disabled, due to poor switching). The debug log says it's generating 22Khz pulses. It didn't work too well on my machine though.

    2. Re:I'm one of those people that hears CRT Monitors by Khith · · Score: 2, Interesting

      I can hear at least up to 20kHz (as high as my speakers' frequency response goes, so I can't test any higher) and it really IS a pain sometimes. The most useful thing I've been able to do is remind them that they left the TV on in the other room. "But I turned off the power and the screen is black.." No, you turned off the power to the cable box which cut out the image and sound on the TV, but I can still hear the flyback transformer. Of course this doesn't work on LCD TVs, though they sometimes just hum or buzz quietly anyway.

      I'm 31 years old. I thought that people around my age weren't supposed to hear such things? Is it all related to one's environment? I don't listen to loud music, avoid loud places, etc, but I still thought that hearing was supposed to diminish.

  9. Re:Activity by Red+Flayer · · Score: 5, Interesting

    Your privacy concerns are valid... however think of the applications for this tech.

    /+5 Hat of Greed equipped.

    Oooh, I'm drooling! Let's see:

    $APP detects two people within viewing distance of your monitor. [click here] to upgrade to the appropriate license.

    /+5 Hat of Greed unequipped.
    /+5 Hat of Stealth equipped.

    Oooh, I'm drooling for different reasons. Let's see:

    $APP detects additional person approaching monitor. Autominimize firefox://ridiculous.pornsite.com; automaximize firefox://romanticweekendgetawayswiththewife.toshowherhowmuchyouloveher.com.

    Whew, that was a close one.

    --
    "Trolls they were, but filled with the evil will of their master: a fell race..." -- J.R.R. Tolkien on Olog-hai
  10. Re:Activity by BitZtream · · Score: 2, Insightful

    Your instant messenger will know when your available or not.
    Your phone system could direct your calls to you mobile if your away from the desk.

    I think this is EXACTLY what he is concerned with. Do you realize how much information you tell others in the world about you with JUST your IM status? Do you realize how easy it is to use this simple bit of information already to plot crimes? Give me a week of watching little more than the IM status of active IMs and twitterers and I can pretty much tell you where you are at during any point in your day if your using a regular schedule.

    He cares and is concerned about this potential problem.

    You haven't even realized how big of a problem it is.

    Roughly speaking, IM status is nearly as good as hang a sign on your home that automatically says 'No One Home!' when you leave.

    --
    Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
  11. How about a license ; how about saying Linux(tm) by rtfa-troll · · Score: 3, Insightful

    It would be nice if they would make the software license clear. Even if just to say that "this is government sponsored and so available for copying with no restrictions". Also at the bottom of the page they say '"Windows" is a registered trademark of the Microsoft Corporation.' but forget to mention that Linux is a registered trademark of Linus Torvalds.

    --
    =~ s,(.*),<sarcasm>$1</sarcasm>,g if any_point_you_wish();
  12. Re:Activity by jijacob · · Score: 2, Informative

    I use blueproximity on ubuntu. Set the distance and it works pretty well to lock (and unlock) my computer when I am away. The unlock could, I'm sure, be easily spoofed, so if you were in a high-sensitivity location you might want to disable the second half of this software.

  13. Re:Activity by maharb · · Score: 3, Insightful

    IM status can be set manually so if you are concerned about privacy... set it manually. Not to mention just because your SYSTEM knows things about you doesn't mean you must pass it on to any app, especially networked ones. Your system knows all sorts of things that it doesn't readily share.

    Believe it or not people can determine all sorts of things about you IRL just by watching too. In fact, IRL, you are way more prone to being tracked and monitored than online. Imagine, someone can see you leave your house, go in, steal shit, and leave all by watching you. We need to fix that bug IRL asap.

    I can't believe the level of unjust paranoia you are experiencing. The fact is if people care enough to track you, they will be able to. It doesn't matter if you have a laptop that turns off when you leave it or not. Also, how does a 5 minute delay from a regular inactivity time out differ from this so much that this tech is all of the sudden dangerous. It seems to me like people can be monitored via IM just as easy right now as if this was being widely used, just with a tad bit more 'false present' status existing.

  14. Why ? by smoker2 · · Score: 2, Interesting

    What's wrong with a keyboard shortcut key or assigning a function key ? It's a laptop, you probably don't just walk away frequently and leave it unattended. Not anywhere I know anyway.

  15. I'm just a slave to the machine... by Kazoo+the+Clown · · Score: 2, Interesting

    Just tell me where I put the postit note or soda bottle to fake it out so it thinks I'm there all the time...

  16. Re:Activity by rockNme2349 · · Score: 2, Funny

    Like batman?

    --
    Sewage Treatment Facilities - "Our duty is clear."
  17. Re:Activity by socceroos · · Score: 2, Insightful

    I would suggest that if you were in a high-sensitivity location you shouldn't have this software at all. Because, all it would take is for someone to keep your desktop from locking when you walk away by spoofing your bluetooth connection.

  18. Re:How about a license ; how about saying Linux(tm by olau · · Score: 3, Interesting

    You got that backwards. What they should do is deleting the remark about Windows. Anyone succumbing to the (tm) crap should have their head examined. Every time somebody writes "registered trademark", god kills a kitten. It's true. Between us, we just killed two. No, I'm not going to write it again.

    Now someone is going to say legal blahblah necessary blahblah. But there is something wrong if fear of a big corporation is making you write that kind of kitten-lethal nonsense every time you mention a product made by that corporation.

  19. So the device in Dark Knight by geekoid · · Score: 2, Interesting

    Could be built. Interesting.

    --
    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  20. Re:Activity by geekoid · · Score: 2, Funny

    Write a script to move the mouse for you. just a few pixels will do.

    --
    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  21. Re:Bat Country? by Bat+Country · · Score: 3, Funny

    I use an HP Pavillion dv6, but I'd prefer something with a touchscreen.

    Thanks for asking!

    --
    The land shall stone them with the bread of his son.
  22. Re:Activity by Chris+Burke · · Score: 3, Funny

    Also, how does a 5 minute delay from a regular inactivity time out differ from this so much that this tech is all of the sudden dangerous. It seems to me like people can be monitored via IM just as easy right now as if this was being widely used, just with a tad bit more 'false present' status existing.

    Because 5 minutes is the maximum amount of time I can be outside before I get scared of the big ball of fire in the sky and have to run back in. If the crooks think I'm home that whole time, I'll always be safe.

    --

    The enemies of Democracy are
  23. Comment removed by account_deleted · · Score: 3, Informative

    Comment removed based on user account deletion

  24. simple solution! by garyebickford · · Score: 2, Funny

    I have a simple solution to that problem. I used to have similar problems (though not as bad) - the 15KHz whistle of the old color TVs used to bug me. But during my misspent youth I spent several years listening to lots of loud music - 10 feet from the speakers at rock concerts, etc. Now, other than a constant ringing in my ears, I'm fine! And I no longer hear HF audio, so no more annoying whistles for me :D Try it, soon you'll be as deaf as Pete Townsend!

    (FYI, the last band I was in used in-ear monitors - Story about deaf musicians and using in-ear monitors. It wasn't even a loud band, but it was nice being able to mix our own levels without worrying about the house levels.

    --
    It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
  25. Re:Activity by RMH101 · · Score: 2, Insightful

    How would you suggest turning off a laptop mic? No hardware switch to do so (unless you've a BIOS option to do it, which I doubt). You could disable the sound card in device manager, but then you've no audio. Seems a valid security issue - nothing stopping an app turning it up in the mixer and recording...