A radio in your mouth.

I’ve read about people whose metal fillings can apparently pick up radio stations. If this is true how exactly does it work, I’m guessing that the radio waves are at the reasonant frequency of the fillings and make them vibrate creating the sound? Am I correct, even if I am I’d appreciate the finer details of the process, it can’t be all that simple.

This actually happened to my mother. She thought she was going insane. She didn’t hear anything during the day with the ambient noise levels and her level of concentration, but at night… La Musica, La Musica! She was getting a Spanish station. Her dentist said it was odd, but not completely uncommon; he simply removed the new filling, and put a new one in. From what I understand, the filling itself acts as the radio crystal, and your whole head becomes the speaker. Your machine is powered by the battery that is formed when the metal in the filling contacts your saliva. I would assume this wouldn’t work with the newer non-metallic fillings.

Ahem.

http://www.straightdope.com/classics/a3_057.html

Just replying for a couple of reasons.

  1. Include me in the group of mouth radio people. Only once and briefly. I bit down hard on something and jammed a filling. All of a sudden there was music playing to my right. (A blank wall.) “What the …?” and I turned my head and the music moved. Oooh. As the pressure in the filling subsided so did the music.

  2. excitable boy: I think the reason your mother heard the radio only at night is that some AM stations are allowed to increase their power after dark (once the daylight only stations go off the air).
    Now: I have researched this over the years and I have a serious problem with the standard “maybe it’s like this” explanations. I built crystal radios as a kid and know quite a bit about electronics. Fillings generate current: easy. A spot on a filling acting as a rectifier (demodulator): simple. A tiny current turning your head into a speaker: hokum.

A better conjecture:

The modulated signal goes does the tooth’s nerve, parallels the nerves coming from the ear, some signal bleed, etc. Brain get’s sound.

But the inner ear has already pre-processed sound into separate frequencies. The nerves are sending each separately to the brain. The brain couldn’t possibly be doing its own little Fourier Transform on its own for these Special Occasions.

Welcome to my lunatic fringe:

In the cochlea there is a membrane that acts as a signal amplifier. Sound passing over it causes it to vibrate and a feedback mechanism occurs. The nerves that control this are easily damaged and some people with tinnitis have a problem with the feedback out of control. Like a Who record. You can actually hear their ringing outside the ear with a sensitive stethescope.

So, signal from tooth nerve, to area of inner ear, to the feedback nerve, makes the membrane vibrate, you hear Kenny G and take the gas.

For the experimentalists out there: Cut the wires off some headphones, stick 'em in your mouth against some fillings, crank up Black Sabbath and have fun explaining it to the ER admissions clerk. (Note: this is a joke, okay?)

FtG aka GLP