8 ms·

When I place my smartphone on the desk near the computer speakers any time it is going to ring the speakers start making a funny noise a second or two before th

When I place my smartphone on the desk near the computer speakers any time it is going to ring the speakers start making a funny noise a second or two before the ringing starts. So I presume it must be possible to DIY a cheap sensor for GSM signal detection based on a little speaker.

retox 10y ago
This is a silly question but I'd like to understand if it's possible for a human to sense those same signals. So many times I have had a sensation that my phone will ring and then moments later it does. Probably confirmation bias or maybe I'm subconsciously hearing the interference in speakers and taking the hint from there. It doesn't happen every time and I don't receive a lot of calls. HN seems a decent place to settle it once and for all.
- kcorbitt 10y ago
  It seems very unlikely that you would be able to sense those frequencies, except indirectly through something like audible speaker interference. However, this would be pretty easy to test! Just have a friend call you at random times throughout a 2-hour interval or something, and record every time you think the phone is about to ring, and every time it actually does. If there's a close enough correlation between the two, that's fairly persuasive evidence.
  - sdkjfwiluf 10y ago
    please please do it!
  - michaelvoz 10y ago
    This is still anecdotal. You would need hundreds of people, also, the very fact that you are expecting calls pollutes that experiment already...
    - monocasa 10y ago
      A large sample size of people isn't necessary to verify the ability. Case in point, the woman who can smell Parkinson's disease, to some ridunculous p-value. http://www.scientificamerican.com/article/one-woman-s-ability-to-sniff-out-parkinson-s-offers-hope-to-sufferers/ http://www.scientificamerican.com/article/one-woman-s-abilit...
    - pessimizer 10y ago
      It's not anecdotal if it's consistently repeatable. You would only need hundreds of people if you were trying to prove that everyone could do it.
    - Iv 10y ago
      You can measure the probability of achieving the result at random and determine the statistical significance of your experiment. Being able to successfully anticipate a call within 10 seconds in a 2 hours interval yields a p < 0.01 Some effects published in medical journals have a less convincing p-value.
    - curried_haskell 10y ago
      And ensure that he records all the false positives
  - greggman 10y ago
    I'd expect it to be audio-ish. I can hear my Macbook Pro compute. AFAIK there's no moving parts except the fan but certain programs I can audibly hear something going on inside the machine. It's kind of annoying as I wish it was silent. Note I'm not saying I have any special ability. I'm sure if I had a sensitive mic I could amplify the sounds.
    - mkesper 10y ago
      This could simply be some capacitor or fan issues.
      - yourad_io 10y ago
        Former Dell XPS 13 Sputnik (9333 model) user checking in. A decent dev machine for $2K-ish, save for a major flaw: "coil whine"[1]. Very annoying when working in silent environments. Frustratingly random as well - for me, backlight on/off, usb connect/disconnect and scrolling on browsers would change the whine frequency noticably. [2] It is possible that you can hear something similar from your MBP - however it is very unlikely that this has anything to do with any of the radios. I miss the good old days when you knew your PC was busy by the HD sounding like a thousand monkeys tap-dancing shakespear. [1] https://en.wikipedia.org/wiki/Coil_noise https://en.wikipedia.org/wiki/Coil_noise [2] BTW, Dell denies this issue, claiming it was fixed before 9333. Users disagree: https://www.reddit.com/r/Dell/comments/47g46m/lets_investigate_the_xps_1315_coil_whine_hardware/ https://www.reddit.com/r/Dell/comments/47g46m/lets_investiga...
  - huuu 10y ago
    "It seems very unlikely that you would be able to sense those frequencies" Is this true? What about heat radiation for example. We can feel that. And we can see/sense changes in electromagnetic fields: http://www.nature.com/ncomms/journal/v2/n6/full/ncomms1364.html http://www.nature.com/ncomms/journal/v2/n6/full/ncomms1364.h...
- spraak 10y ago
  Very hand wavy of me, but I'd say there is a way that it's true you can sense it. We may not yet know how you can, though. An example that I like to think of is of infrasound. People can't hear it, but there are some who sense when it's moving through them.
- dingaling 10y ago
  People have long reported experiencing radio reception through tooth fillings, usually in the ham and FM bands from 1 to around 100 MHz. I can imagine cell frequencies would be even more likely due to smaller antennae for the higher frequency.
  - milesokeefe 10y ago
    It's not conclusive by any means but Mythbusters tested this and came to the conclusion that tooth filings don't act as an antennae: http://mythresults.com/episode4 http://mythresults.com/episode4
    - timthorn 10y ago
      But do some, imperfectly fitting, filings act as a diode?
    - nitrogen 10y ago
      Sometimes the Mythbusters do interesting things, but their ad hoc methods, largely uninformed by theory, are often so haphazard that they prove basically nothing.
      - imglorp 10y ago
        Well, if they can manage to reproduce a phenomenon, however they stumble on it, it's pretty conclusively confirmed. There's definitely doubt about their conclusion when they can't reproduce something and then declare it busted -- absence of evidence is not evidence of absence.
        nitrogen 10y ago
        I can think of one "confirmed" myth involving bacteria that was likely invalidated by improper sample handling. The lab scientist who ran the test appeared to be straining to say that without overstepping her remit on the show.
- kosmic_k 10y ago
  I don't believe that humans can really sense it on their own. But there was/is a group of "body hackers" who would implant a small shard of a magnet into their finger tip to allow them to feel electromagnetic fields.
- reitanqild 10y ago
  At some point during some school work I felt I could sense when someone tried to call me on my parents landline. More then half my life has passed since then and I have never felt close to replicating so I guess most likely my subconsciousness figured out some patterns in who called when. Another observation though: I worked professionally with radar systems for a while and IIRC one of the oldtimers mentioned one isolated case where a person had been able to tell when a certain radar was transmitting in his sector. (Radars often only transmit in sectors turning away from the population.) But, to be honest, I haven't heard about it anywhere else and most people who claim to sense that kind of radiation either refuses to undergo blind studies or fail them so if you treat this as anything but an old wives tale you have to do your research :-)
- deleted 10y ago
  [deleted]
- elif 10y ago
  Scientifically: There are people from disparate countries who believe that they suffer from a condition called `EM hypersensitivity`, and are convinced they must live in remote areas away from radios to avoid sickness or headaches. In the handful of published studies that exist, evidence points to an inability of these people to distinguish between exposure and non-exposure in a laboratory setting. Anecdotally: I can definitely "feel" large AC transmission lines. They do have an audible buzz, however the "feeling" sensation seems distinct to me. My experience is from hiking the Appalachian Trail, which spends days outside of cell phone range, and then crosses regional transmission lines periodically. So if that observation is not pure illusion or auditory synesthesia (perhaps a fully deaf person can assist here?), it would seem to follow that there is a mechanism to sense EM radiation, and it is simply a matter of whether the perceptive threshold has been met, which would obviously vary from person to person and even from instant to instant.
  - speeder 10y ago
    I remembered now of a church pastor I know, that was an antenna. The story: this pastor, and only this pastor, would make wireless microphones in certain frequencies act up. Eventually the audio team found out that somehow this particular pastor worked as an antenna for a particular frequency, matching a nearby radio transmitter, that due to its enormous size would overpower the microphone transmission and corrupt the data.
    - white-flame 10y ago
      One of my friends has a magnetic butt. Any time he carries a mag strip card in his back pocket, it no longer works. I also knew somebody who had to use wind-up pocket watches, because quartz wristwatches would always skew when he wore them, but would keep time fine when removed. Weird stuff. Who knows.
      - stillworks 10y ago
        And how about the wind-up watches ? Did they not skew :-)
    - 10y ago
- kleskjr 10y ago
  Theoretically it might be possible. There are some studies on the effects of electric fields onto single neurons. If an external field can influence the firing of neurons in some way, probably one can train to read these signals. http://journal.frontiersin.org/article/10.3389/fncel.2014.00310/full http://journal.frontiersin.org/article/10.3389/fncel.2014.00... I have no idea on what field intensities are sufficient to influence the neurons.
- deleted 10y ago
  [deleted]
- deleted 10y ago
  [deleted]
- iaskwhy 10y ago
  I'm curious about animals other than humans. Once I was waiting for a call by a window, there was a generous spider on the other side. As I'm very afraid of spiders, I was looking at it while waiting for that call to arrive, it was very calm, barely moving. As soon as the call showed on the screen, silent mode on, no sound or vibration, the spider got completely mad, moving around like crazy so I moved away and the spider stopped moving again. I did experiment moving closer and away repeatedly with the same result. So maybe spiders are sensitive to that frequency?
agumonkey 10y ago
These are GSM/3G signals. I never hear anything when transmitting wifi or bluetooth.
- Zigurd 10y ago
  You would need a GSM phone, not just a speaker. Your phone's radio can interfere with electronics like land-line phones. My Nexus 5, on a GSM/LTE network, will cause my Polycom speakerphone to make "dit-dit-dit" noises occasionally (when the network interrogates devices in range) if it is with a few inches of the speakerphone. I suspect people who think they can sense a call coming in are hearing the network looking for their phone in order to offer a call, and not sensing radio waves.
secfirstmd 10y ago
That was an old IRA technique to detect certain types of signals nearby. Cheap headphones and a modified radio of sorts. Looking for interference.
- 13of40 10y ago
  I have no idea how this happened, but about twenty years ago, I had an internal PC modem that started randomly speaking to me about fire, brimstone, salvation, etc. Thought I was going off my rocker, until I figured out that it was picking up an AM religious station and playing it through the onboard speaker. My best guess is that somewhere on the circuit board there was a diode and a capacitor just in the right spot and it was using the phone line as an antenna.
  - secfirstmd 10y ago
    "fire, brimstone, salvation" sounds like you grew up in Northern Ireland alright :)
roflchoppa 10y ago
its probably signal interference because i get it too. " beep-beep-beep ; beep-beep-beep ; beep-beep-beep ; beeeeeeeeee" then call or text comes through
Qantourisc 10y ago
Use old style opamps for this btw, they are more susceptible to this, like LM741 NE553, LM883, ... If you are ok with putting your cellphone on the detection box, all you need is an opamp driving a small speaker, and the opamp requires no input. Or you could just hook an antenna on it. If you want I could try, but I have more exiting things to do :)
vincnetas 10y ago
Mobile flashing stickers powered by RF from your phone (no batteries) : https://www.alibaba.com/product-detail/GSM-mobile-led-flashing-sticker_521197206.html https://www.alibaba.com/product-detail/GSM-mobile-led-flashi... [EDIT] http://electronics.stackexchange.com/questions/38838/powering-an-led-from-rf-cellphone-signals http://electronics.stackexchange.com/questions/38838/powerin...
- greggman 10y ago
  Those stickers are cool. Japan had various dangly things to attach to your feature phone that worked similarly for years. Smartphones generally have no place to attach anything so they seem to have mostly disappeared.

retox 10y ago

This is a silly question but I'd like to understand if it's possible for a human to sense those same signals. So many times I have had a sensation that my phone will ring and then moments later it does. Probably confirmation bias or maybe I'm subconsciously hearing the interference in speakers and taking the hint from there. It doesn't happen every time and I don't receive a lot of calls. HN seems a decent place to settle it once and for all.

kcorbitt 10y ago
It seems very unlikely that you would be able to sense those frequencies, except indirectly through something like audible speaker interference. However, this would be pretty easy to test! Just have a friend call you at random times throughout a 2-hour interval or something, and record every time you think the phone is about to ring, and every time it actually does. If there's a close enough correlation between the two, that's fairly persuasive evidence.
- sdkjfwiluf 10y ago
  please please do it!
- michaelvoz 10y ago
  This is still anecdotal. You would need hundreds of people, also, the very fact that you are expecting calls pollutes that experiment already...
  - monocasa 10y ago
    A large sample size of people isn't necessary to verify the ability. Case in point, the woman who can smell Parkinson's disease, to some ridunculous p-value. http://www.scientificamerican.com/article/one-woman-s-ability-to-sniff-out-parkinson-s-offers-hope-to-sufferers/ http://www.scientificamerican.com/article/one-woman-s-abilit...
  - pessimizer 10y ago
    It's not anecdotal if it's consistently repeatable. You would only need hundreds of people if you were trying to prove that everyone could do it.
  - Iv 10y ago
    You can measure the probability of achieving the result at random and determine the statistical significance of your experiment. Being able to successfully anticipate a call within 10 seconds in a 2 hours interval yields a p < 0.01 Some effects published in medical journals have a less convincing p-value.
  - curried_haskell 10y ago
    And ensure that he records all the false positives
- greggman 10y ago
  I'd expect it to be audio-ish. I can hear my Macbook Pro compute. AFAIK there's no moving parts except the fan but certain programs I can audibly hear something going on inside the machine. It's kind of annoying as I wish it was silent. Note I'm not saying I have any special ability. I'm sure if I had a sensitive mic I could amplify the sounds.
  - mkesper 10y ago
    This could simply be some capacitor or fan issues.
    - yourad_io 10y ago
      Former Dell XPS 13 Sputnik (9333 model) user checking in. A decent dev machine for $2K-ish, save for a major flaw: "coil whine"[1]. Very annoying when working in silent environments. Frustratingly random as well - for me, backlight on/off, usb connect/disconnect and scrolling on browsers would change the whine frequency noticably. [2] It is possible that you can hear something similar from your MBP - however it is very unlikely that this has anything to do with any of the radios. I miss the good old days when you knew your PC was busy by the HD sounding like a thousand monkeys tap-dancing shakespear. [1] https://en.wikipedia.org/wiki/Coil_noise https://en.wikipedia.org/wiki/Coil_noise [2] BTW, Dell denies this issue, claiming it was fixed before 9333. Users disagree: https://www.reddit.com/r/Dell/comments/47g46m/lets_investigate_the_xps_1315_coil_whine_hardware/ https://www.reddit.com/r/Dell/comments/47g46m/lets_investiga...
- huuu 10y ago
  "It seems very unlikely that you would be able to sense those frequencies" Is this true? What about heat radiation for example. We can feel that. And we can see/sense changes in electromagnetic fields: http://www.nature.com/ncomms/journal/v2/n6/full/ncomms1364.html http://www.nature.com/ncomms/journal/v2/n6/full/ncomms1364.h...
spraak 10y ago
Very hand wavy of me, but I'd say there is a way that it's true you can sense it. We may not yet know how you can, though. An example that I like to think of is of infrasound. People can't hear it, but there are some who sense when it's moving through them.
dingaling 10y ago
People have long reported experiencing radio reception through tooth fillings, usually in the ham and FM bands from 1 to around 100 MHz. I can imagine cell frequencies would be even more likely due to smaller antennae for the higher frequency.
- milesokeefe 10y ago
  It's not conclusive by any means but Mythbusters tested this and came to the conclusion that tooth filings don't act as an antennae: http://mythresults.com/episode4 http://mythresults.com/episode4
  - timthorn 10y ago
    But do some, imperfectly fitting, filings act as a diode?
  - nitrogen 10y ago
    Sometimes the Mythbusters do interesting things, but their ad hoc methods, largely uninformed by theory, are often so haphazard that they prove basically nothing.
    - imglorp 10y ago
      Well, if they can manage to reproduce a phenomenon, however they stumble on it, it's pretty conclusively confirmed. There's definitely doubt about their conclusion when they can't reproduce something and then declare it busted -- absence of evidence is not evidence of absence.
      - nitrogen 10y ago
        I can think of one "confirmed" myth involving bacteria that was likely invalidated by improper sample handling. The lab scientist who ran the test appeared to be straining to say that without overstepping her remit on the show.
kosmic_k 10y ago
I don't believe that humans can really sense it on their own. But there was/is a group of "body hackers" who would implant a small shard of a magnet into their finger tip to allow them to feel electromagnetic fields.
reitanqild 10y ago
At some point during some school work I felt I could sense when someone tried to call me on my parents landline. More then half my life has passed since then and I have never felt close to replicating so I guess most likely my subconsciousness figured out some patterns in who called when. Another observation though: I worked professionally with radar systems for a while and IIRC one of the oldtimers mentioned one isolated case where a person had been able to tell when a certain radar was transmitting in his sector. (Radars often only transmit in sectors turning away from the population.) But, to be honest, I haven't heard about it anywhere else and most people who claim to sense that kind of radiation either refuses to undergo blind studies or fail them so if you treat this as anything but an old wives tale you have to do your research :-)
deleted 10y ago
[deleted]
elif 10y ago
Scientifically: There are people from disparate countries who believe that they suffer from a condition called `EM hypersensitivity`, and are convinced they must live in remote areas away from radios to avoid sickness or headaches. In the handful of published studies that exist, evidence points to an inability of these people to distinguish between exposure and non-exposure in a laboratory setting. Anecdotally: I can definitely "feel" large AC transmission lines. They do have an audible buzz, however the "feeling" sensation seems distinct to me. My experience is from hiking the Appalachian Trail, which spends days outside of cell phone range, and then crosses regional transmission lines periodically. So if that observation is not pure illusion or auditory synesthesia (perhaps a fully deaf person can assist here?), it would seem to follow that there is a mechanism to sense EM radiation, and it is simply a matter of whether the perceptive threshold has been met, which would obviously vary from person to person and even from instant to instant.
- speeder 10y ago
  I remembered now of a church pastor I know, that was an antenna. The story: this pastor, and only this pastor, would make wireless microphones in certain frequencies act up. Eventually the audio team found out that somehow this particular pastor worked as an antenna for a particular frequency, matching a nearby radio transmitter, that due to its enormous size would overpower the microphone transmission and corrupt the data.
  - white-flame 10y ago
    One of my friends has a magnetic butt. Any time he carries a mag strip card in his back pocket, it no longer works. I also knew somebody who had to use wind-up pocket watches, because quartz wristwatches would always skew when he wore them, but would keep time fine when removed. Weird stuff. Who knows.
    - stillworks 10y ago
      And how about the wind-up watches ? Did they not skew :-)
  - 10y ago
kleskjr 10y ago
Theoretically it might be possible. There are some studies on the effects of electric fields onto single neurons. If an external field can influence the firing of neurons in some way, probably one can train to read these signals. http://journal.frontiersin.org/article/10.3389/fncel.2014.00310/full http://journal.frontiersin.org/article/10.3389/fncel.2014.00... I have no idea on what field intensities are sufficient to influence the neurons.
deleted 10y ago
[deleted]
deleted 10y ago
[deleted]
iaskwhy 10y ago
I'm curious about animals other than humans. Once I was waiting for a call by a window, there was a generous spider on the other side. As I'm very afraid of spiders, I was looking at it while waiting for that call to arrive, it was very calm, barely moving. As soon as the call showed on the screen, silent mode on, no sound or vibration, the spider got completely mad, moving around like crazy so I moved away and the spider stopped moving again. I did experiment moving closer and away repeatedly with the same result. So maybe spiders are sensitive to that frequency?

agumonkey 10y ago

These are GSM/3G signals. I never hear anything when transmitting wifi or bluetooth.

Zigurd 10y ago
You would need a GSM phone, not just a speaker. Your phone's radio can interfere with electronics like land-line phones. My Nexus 5, on a GSM/LTE network, will cause my Polycom speakerphone to make "dit-dit-dit" noises occasionally (when the network interrogates devices in range) if it is with a few inches of the speakerphone. I suspect people who think they can sense a call coming in are hearing the network looking for their phone in order to offer a call, and not sensing radio waves.

secfirstmd 10y ago

That was an old IRA technique to detect certain types of signals nearby. Cheap headphones and a modified radio of sorts. Looking for interference.

13of40 10y ago
I have no idea how this happened, but about twenty years ago, I had an internal PC modem that started randomly speaking to me about fire, brimstone, salvation, etc. Thought I was going off my rocker, until I figured out that it was picking up an AM religious station and playing it through the onboard speaker. My best guess is that somewhere on the circuit board there was a diode and a capacitor just in the right spot and it was using the phone line as an antenna.
- secfirstmd 10y ago
  "fire, brimstone, salvation" sounds like you grew up in Northern Ireland alright :)

roflchoppa 10y ago

its probably signal interference because i get it too. " beep-beep-beep ; beep-beep-beep ; beep-beep-beep ; beeeeeeeeee" then call or text comes through

Qantourisc 10y ago

Use old style opamps for this btw, they are more susceptible to this, like LM741 NE553, LM883, ... If you are ok with putting your cellphone on the detection box, all you need is an opamp driving a small speaker, and the opamp requires no input. Or you could just hook an antenna on it. If you want I could try, but I have more exiting things to do :)

vincnetas 10y ago

Mobile flashing stickers powered by RF from your phone (no batteries) : https://www.alibaba.com/product-detail/GSM-mobile-led-flashing-sticker_521197206.html https://www.alibaba.com/product-detail/GSM-mobile-led-flashi... [EDIT] http://electronics.stackexchange.com/questions/38838/powering-an-led-from-rf-cellphone-signals http://electronics.stackexchange.com/questions/38838/powerin...

greggman 10y ago
Those stickers are cool. Japan had various dangly things to attach to your feature phone that worked similarly for years. Smartphones generally have no place to attach anything so they seem to have mostly disappeared.