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Comment by speedylight | Hacker News Reader

I’ve heard that some people with amalgam tooth filling can sometimes pick up transmissions and somehow audio would actually play inside their mouth, not static noise, actual voices talking. It’s quite bizarre but also makes total sense when you think about it!

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It sounds like it's still on open question as to whether or not this is possible.

This story was the one that came to mind when I say your comment and the post makes for a quick, interesting read.

https://www.snopes.com/fact-check/lucille-ball-fillings-spie...

In this video they can apparently hear the transmission by holding a blade of grass against the transmitter https://www.youtube.com/watch?v=b9UO9tn4MpI

The video looks convincing but it could also be faked, and I don't think it's possible. The signal coming into the radio tower (which is basically just a big antenna) would already be modulated to a much higher frequency (702khz or whatever).

I guess there could be some other effect that makes it audible when you hold a blade of grass or a hotdog to the transmitter, but I don't think it would be intuitive.

I've gotten a transmission through my radiator via earth to my computer speakers somehow. With the volume at 0 it still played but was cut when I touched the radiator.

I thought I was going cracy when turning the volume to zero did not cut it before I realized it was radio hehe.

Maybe there can be accidental demodulation somehow?

If you're next to the transmitter, even a wrench can be a receiver. It's a function of power and the am towers put out a shit ton

When there's enough transmitted power, everything turns into a receiver. Besides the infamous tooth fillings mentioned, and the demonstration videos shown around here at the antenna, there's been plenty other reports of things like bedsprings, pipes, and fences converting AM broadcasts into sound.

https://www.youtube.com/watch?v=GHSuInSkHtA

AM is just power, its why crystal radios work...

"The video looks convincing but it could also be faked"

I don't think it's faked, what's shown here is what you'd expect. I've been on 'live' FM towers and the RF burned holes in my jeans at my knees (my knees were rapped around the metal tower and the induced RF in the tower zapped holes through the material in my jeans and then burned holes in my skin).

On AM the sound that you're hearing is demodulation caused by resistive non-lineararity in the carbon caused by the burning/heating process. This is quite a common phenomenon with high powered AM transmitters.

Unknown to me if that's real, but you can hear AM radio with a sausage of you're next to the transmitter's antenna: https://youtu.be/GgDxXDV4_hc

this is a fantastic demo! just to nitpick, though, it's really the plasma between the sausage and the antenna that's making the sound; the plasma heats up regardless of which direction the current was flowing, so you don't need a 'detector' converting ac to dc as you do in a conventional radio. for fillings the most likely explanation is a parasitic schottky rectifier accidentally formed from a metal oxide, rather than such a resistive phenomenon (though it's not impossible)

You sound a bit credulous :)

The keyword is 'amalgam' - a lead crystal, a bit of wire and a headphone gets you AM reception: https://en.wikipedia.org/wiki/Crystal_radio

(the wire is optional if the signal is strong, and a 'headphone' is anything you can make vibrate with electricity)

I'm sorry but this anecdote sets off my BS detector very hard.

it's probably real but not thoroughly proven: https://www.straightdope.com/21341818/is-it-possible-to-hear...

How on Earth did you arrive at the conclusion "probably real" from that link?

by reading the conclusions contained in the article it links to

That conclusion?

> Whatever the case may be, the available evidence behind this tale appears to be purely anecdotal and not verifiable at this point.

no, the others

I literally quoted the conclusion of the linked snopes article.

the article i linked to wasn't by snopes or on her web site; it was a 'straight dope' column from the chicago reader

funny how all of these cases predate the existence of recording devices, probably because people don’t get dental work anymore

plausibly people don't have many such high-powered am transmitters around any more, but also much less dental work is metal now, and the metal is of more consistent quality, so less chance of oxidizing into one of the numerous metal oxide semiconductors in your mouth. it seems to have been a pretty infrequent phenomenon even at the time, one in tens of millions

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