Is the human nervous system sensitive enough to pick up EMI?

I have a question about the “ticking” sound that audio speakers make when a cell phone is about to ring. I assume that the noise is caused by EMI - electromagnetic interference. My question, which comes by way of a question posed by J. Michael Straczynski to usenet, is paraphrased as follows:

Straczynski said that he is “one of those people who often seems to know when the phone is going to ring.” He also recognizes that this could be, in his words, “synchronicity”. IOW there are many times he looks at a phone and when it doesn’t ring, it doesn’t occur to him to remember that.

So the question is, can the human nervous system be sensitive enough to pick up the EMI from a cell phone? If it is, it might provide a scientific answer to how some people “just know” the phone is about to ring.

I (he) (we) need the Straight Dope.



People who have been in large microwave chambers report the experience as being pleasantly warm, or something along those lines. Since they reported no other effects, and the microwave energy required to heat things is so much higher than that of a cell phone, that I seriously doubt that the human nervous system is capable of detecting such things.

I’d be more inclined to believe that something in the phone is oscillating at a frequency just barely in the infrosonic or ultrasonic range (kind of like how you can hear a camera flash charging) as the phone communicates with the tower. But that’s just a WAG.

I’d like to know more about the large microwave chambers.

I think that’s possible. Plus there are many reports of people hearing stuff through the fillings in their teeth. I know this sounds ridiculous, but I’ll see if I can find a credible citation.

Cecil answers the question Is it possible to hear radio broadcasts through your teeth? He also mentions people hearing “buzzing when irradiated with UHF and VHF radio pulses from 100 feet”. I’m guessing these would be fairly powerful pulses.

Before or after their blood boiled?
J/k, I’d like to hear more about these microwave chambers.

It’s not a cell phone, but you can produce visual effects via transcranial magnetic stimulation. The field strength involved, several Tesla, is far beyond anything a cell phone could ever emit.

Yes, but research with subliminal stimuli have shown that we can have a response to things of which we are not conscously aware. While we may not be able to actually know that we are getting sensory information, doesn’t mean we can’t react to it.

I know when my cell phone that I use for an alarm clock is about to ring the alarm. There is a barely audiable sound made one minute before the alarm. Probable the same thing happens just before the call ring is made. For instance caller ID info is sent in advance of the ringing tone.

Think Cecil said something about this is one of his books in answer to someone who always woke up just before his alarm clock went off.

I recall watching a show where a researcher was examining the visual cortex, to see if it was doing something in people who were blind. Part of that included something like the above magnetic stimulation, in such a way that it tired out the neurons temporarily or something. People who could see couldn’t see details very well for a while, and blind people had problems reading Braille. Kinda neat, but if that was my grad program I’d be looking for another project. :wink:

I think though that the frequency and amplitude are important factors here.

I’ve always thought it was something along the lines of what engineer_comp_geek said. For example, I can always tell when someone has left a computer monitor on. Many solid state devices may emit high frequency sounds that are just on the border of detectable.