5 ms·

> A large, somewhat ungainly white cuff with spiky transducers, the bracelet has 24 speakers that emit ultrasonic signals when the wearer turns it on. The sound

> A large, somewhat ungainly white cuff with spiky transducers, the bracelet has 24 speakers that emit ultrasonic signals when the wearer turns it on. The sound is imperceptible to most ears, with the possible exception of young people and dogs, but nearby microphones will detect the high-frequency sound instead of other noises. This is surely not actually effective against a wide range of well designed, real world microphones, and definitely not against something designed to surreptitiously record you. Strikes me as more of a gimmick than anything else. Full disclosure: I don't have any always-on microphones in my house, and probably never will, so I probably qualify as some kind of techno-skeptic.

hinkley 7y ago
I know more than a couple of older people who can still hear very high pitched whines from electrical equipment. The “only children and dogs” is some bad statistics. Also houses have dogs or kids. Or both. It’s a thing.
- xzel 7y ago
  I’m a bit older than average and these types of things and noises drive me crazy. I can’t even be near some old CRT screens due to the pitch they emit (especially bad with old CCTV monitors).
  - hinkley 7y ago
    I may have lost a little at the high end or electronics have gotten better filters, but I used to grumpily stomp into the next room to turn off the tv or the VCR because it was bugging me. There was a story a few years back about stores getting rid of young loiterers by playing these tones, then later on kids setting ringtones or alerts on their phones so that the teacher wouldn’t get mad that their phones were on. Guess what? A lot of surprised 15 year olds had their phones confiscated by disgruntled 40 year old teachers who could damn well hear the ringtones.
    - JonathonW 7y ago
      The TV noise you used to hear is gone because CRTs are gone-- it comes from the flyback tranformer in the TV, which had a propensity to resonate at the TV's horizontal scanning frequency (somewhere in the ballpark of 15.7 kHz, the exact frequency depending on whether your TV was NTSC or PAL). I had a "I haven't heard that in ages" moment over the summer; was in some shop in the UK that had a CRT showing their CCTV cameras and could hear the thing well before I could see it. Apparently my high-end hearing's still decent.
      - andrewzah 7y ago
        CRTs are almost gone; they’re still highly sought after in the smashbros community. :-) IIRC trinitrons are the most highly desired. Due to the shortage, a "crt vault" was created. [0] I remember visiting multiple thrift stores ~2 years ago to collect them. The most I had was 6 I think, but I ended up giving them to other players. Here's an example of what they look like at tournaments [1] [0]: https://old.reddit.com/r/smashbros/comments/3dzqd9/to_those_who_enjoyed_smash_at_evo_please_thank/ https://old.reddit.com/r/smashbros/comments/3dzqd9/to_those_... [1]: https://www.youtube.com/watch?v=j_WBBeXzUcQ https://www.youtube.com/watch?v=j_WBBeXzUcQ
    - spats1990 7y ago
      The other day my dad, who turned 60 last year, swore he couldn't hear a cicada that was right outside the open window. It bugged him so much he made me go outside with him and point out the cicada. I told him about the mosquito tone, which is obviously much higher, and how mostly only younger people are meant to be able to hear it and played it for him off Wikipedia. He could hear it fine and so could I (30 this year). To hell with the mosquito tone as an anti-loitering device, it's horrible.
  - Freak_NL 7y ago
    Like those high-pitched 'mosquito'-devices installed in places where young people tend to hang out; most adults over 25 can't hear them at all. There is a school here with an apparently inviting set of steps under an awning that activates this device outside of school hours. Passing that building is really annoying. I'm 39.
    - deleted 7y ago
      [deleted]
    - StavrosK 7y ago
      Oh God, I saw one of those in Japan outside a store at night, we came near it and I went "what the hell is that noise?", but none of my friends could hear anything. Turned out to be the mosquito thing, which was quite effective in getting me away from that shop. I was 35 at the time and my friends were 30ish, I guess it varies by person.
      - bencollier49 7y ago
        It's the babies brought into the shops by their oblivious parents that I feel sorry for. Mosquito devices ought to be illegal, it's noise pollution.
- deleted 7y ago
  [deleted]
- EliRivers 7y ago
  I used to be able to hear monitors whine and I'd have to unplug them completely. Can't anymore; I thought it was because I was getting older and my hearing at the higher frequencies was dropping off. Still got one of the monitors I used to be able to hear whine and I can't hear it anymore. Seems odd that there are older people who can hear the high-pitches when younger people can't. Maybe the kids are tuning it out.
kranner 7y ago
> Full disclosure: I don't have any always-on microphones in my house Does this include smartphones, computers, or other such devices capable of becoming always-on microphones in software?
agildehaus 7y ago
> I don't have any always-on microphones in my house, and probably never will, so I probably qualify as some kind of techno-skeptic. That you know of. Every smartphone has a microphone, as do most laptops and desktops.
- h4waii 7y ago
  That you know of also ;) Many privacy-concious people opt for software that allows them to verifiably control their hardware, be it desktop/laptop or smartphone. Some will go the extra step to physically remove or disable microphones and speakers.
  - drewbug 7y ago
    verifiably?
    - astrobe_ 7y ago
      A synonym for "open source".
      - acdha 7y ago
        Open source would only be the start: you still need to build or forensically audit each component (hardware or software) or you’re fooling yourself.
        Fnoord 7y ago
        Reproducible builds.
  - saagarjha 7y ago
    > Many privacy-concious people opt for software that allows them to verifiably control their hardware, be it desktop/laptop or smartphone. I know a fair number of privacy-concious people, and not one of them have any sort of verifiable control of their hardware. It's surprisingly hard to do this, it turns out…
endless1234 7y ago
It's an one off art project, not an actual product they're aiming to start selling. Of course it's a "gimmick", that's not the point.
dijksterhuis 7y ago
Dolphin Attack used ultrasonic amplitude modulation against a variety of devices with some success [0]. Page 9 for the results table. I believe they were taking advantage of the non linearity of microphones. 0: https://arxiv.org/pdf/1708.09537.pdf https://arxiv.org/pdf/1708.09537.pdf
endorphone 7y ago
I suspect that it would only work against MEMS microphones. Normal "analog" magnetic microphones physically filter high frequency noise.

hinkley 7y ago

I know more than a couple of older people who can still hear very high pitched whines from electrical equipment. The “only children and dogs” is some bad statistics. Also houses have dogs or kids. Or both. It’s a thing.

xzel 7y ago
I’m a bit older than average and these types of things and noises drive me crazy. I can’t even be near some old CRT screens due to the pitch they emit (especially bad with old CCTV monitors).
- hinkley 7y ago
  I may have lost a little at the high end or electronics have gotten better filters, but I used to grumpily stomp into the next room to turn off the tv or the VCR because it was bugging me. There was a story a few years back about stores getting rid of young loiterers by playing these tones, then later on kids setting ringtones or alerts on their phones so that the teacher wouldn’t get mad that their phones were on. Guess what? A lot of surprised 15 year olds had their phones confiscated by disgruntled 40 year old teachers who could damn well hear the ringtones.
  - JonathonW 7y ago
    The TV noise you used to hear is gone because CRTs are gone-- it comes from the flyback tranformer in the TV, which had a propensity to resonate at the TV's horizontal scanning frequency (somewhere in the ballpark of 15.7 kHz, the exact frequency depending on whether your TV was NTSC or PAL). I had a "I haven't heard that in ages" moment over the summer; was in some shop in the UK that had a CRT showing their CCTV cameras and could hear the thing well before I could see it. Apparently my high-end hearing's still decent.
    - andrewzah 7y ago
      CRTs are almost gone; they’re still highly sought after in the smashbros community. :-) IIRC trinitrons are the most highly desired. Due to the shortage, a "crt vault" was created. [0] I remember visiting multiple thrift stores ~2 years ago to collect them. The most I had was 6 I think, but I ended up giving them to other players. Here's an example of what they look like at tournaments [1] [0]: https://old.reddit.com/r/smashbros/comments/3dzqd9/to_those_who_enjoyed_smash_at_evo_please_thank/ https://old.reddit.com/r/smashbros/comments/3dzqd9/to_those_... [1]: https://www.youtube.com/watch?v=j_WBBeXzUcQ https://www.youtube.com/watch?v=j_WBBeXzUcQ
  - spats1990 7y ago
    The other day my dad, who turned 60 last year, swore he couldn't hear a cicada that was right outside the open window. It bugged him so much he made me go outside with him and point out the cicada. I told him about the mosquito tone, which is obviously much higher, and how mostly only younger people are meant to be able to hear it and played it for him off Wikipedia. He could hear it fine and so could I (30 this year). To hell with the mosquito tone as an anti-loitering device, it's horrible.
- Freak_NL 7y ago
  Like those high-pitched 'mosquito'-devices installed in places where young people tend to hang out; most adults over 25 can't hear them at all. There is a school here with an apparently inviting set of steps under an awning that activates this device outside of school hours. Passing that building is really annoying. I'm 39.
  - deleted 7y ago
    [deleted]
  - StavrosK 7y ago
    Oh God, I saw one of those in Japan outside a store at night, we came near it and I went "what the hell is that noise?", but none of my friends could hear anything. Turned out to be the mosquito thing, which was quite effective in getting me away from that shop. I was 35 at the time and my friends were 30ish, I guess it varies by person.
    - bencollier49 7y ago
      It's the babies brought into the shops by their oblivious parents that I feel sorry for. Mosquito devices ought to be illegal, it's noise pollution.
deleted 7y ago
[deleted]
EliRivers 7y ago
I used to be able to hear monitors whine and I'd have to unplug them completely. Can't anymore; I thought it was because I was getting older and my hearing at the higher frequencies was dropping off. Still got one of the monitors I used to be able to hear whine and I can't hear it anymore. Seems odd that there are older people who can hear the high-pitches when younger people can't. Maybe the kids are tuning it out.

kranner 7y ago

> Full disclosure: I don't have any always-on microphones in my house Does this include smartphones, computers, or other such devices capable of becoming always-on microphones in software?

agildehaus 7y ago

> I don't have any always-on microphones in my house, and probably never will, so I probably qualify as some kind of techno-skeptic. That you know of. Every smartphone has a microphone, as do most laptops and desktops.

h4waii 7y ago
That you know of also ;) Many privacy-concious people opt for software that allows them to verifiably control their hardware, be it desktop/laptop or smartphone. Some will go the extra step to physically remove or disable microphones and speakers.
- drewbug 7y ago
  verifiably?
  - astrobe_ 7y ago
    A synonym for "open source".
    - acdha 7y ago
      Open source would only be the start: you still need to build or forensically audit each component (hardware or software) or you’re fooling yourself.
      - Fnoord 7y ago
        Reproducible builds.
- saagarjha 7y ago
  > Many privacy-concious people opt for software that allows them to verifiably control their hardware, be it desktop/laptop or smartphone. I know a fair number of privacy-concious people, and not one of them have any sort of verifiable control of their hardware. It's surprisingly hard to do this, it turns out…

endless1234 7y ago

It's an one off art project, not an actual product they're aiming to start selling. Of course it's a "gimmick", that's not the point.

dijksterhuis 7y ago

Dolphin Attack used ultrasonic amplitude modulation against a variety of devices with some success [0]. Page 9 for the results table. I believe they were taking advantage of the non linearity of microphones. 0: https://arxiv.org/pdf/1708.09537.pdf https://arxiv.org/pdf/1708.09537.pdf

endorphone 7y ago

I suspect that it would only work against MEMS microphones. Normal "analog" magnetic microphones physically filter high frequency noise.