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Q: Radio signals picked up by tooth fillings. ( Answered 5 out of 5 stars,   2 Comments )
Subject: Radio signals picked up by tooth fillings.
Category: Science
Asked by: firebird-ga
List Price: $15.00
Posted: 29 Jun 2004 17:05 PDT
Expires: 29 Jul 2004 17:05 PDT
Question ID: 367925
Is it scientifically verifiable that tooth fillings (or metal that
perhaps for medical reasons are implanted) are able to pick up radio
Subject: Re: Radio signals picked up by tooth fillings.
Answered By: tlspiegel-ga on 29 Jun 2004 19:29 PDT
Rated:5 out of 5 stars
Hi firebird,

Thank you for a most interesting question!  

(The short answer to your question is:  Yes, No, Maybe.)   

Stories of tooth fillings acting as receivers to pick up radio signals
has long been debated as a possible urban myth.  (Emphasis on

However, many people claim to have heard radio signals coming from
tooth fillings or braces.


Alaska Science Forum
February 9, 1995

"This column is provided as a public service by the Geophysical
Institute, University of Alaska Fairbanks, in cooperation with the UAF
research community. Ned Rozell, is a science writer at the institute.

It's one of life's little irritations---I answer my telephone, and the
person on the other end sounds a lot like Elvis. Then I realize that a
local a.m. radio station is broadcasting an Elvis song, which is
somehow being picked up by my phone and competing with the caller for
my ear.

How does my phone turn into a radio receiver? I spent four years in
the Air Force working on radios, and I remember the receivers as
rather large, complicated boxes, crammed with tiny electrical
components and a web of wires. My phone doesn't seem that complicated.

According to Robert Hunsucker, a professor emeritus at the Geophysical
Institute with the University of Alaska Fairbanks, my phone isn't that
complicated, and neither is a receiver circuit. A receiver is so
simple, Hunsucker said, that anything from a phone to a person's mouth
can act as one.

At its most basic, a receiver circuit consists of only three elements:
an antenna, which picks up an electromagnetic radio signal; a
detector, which is an electrical component that converts the radio
wave to an audio signal the human ear can pick up; and a transducer,
which is anything that acts like a speaker."


"The direct-current voltage produced by the diode has peaks and
valleys that correspond to Elvis's voice and the sound of his backup
band. This voltage is felt and expressed by a transducer, which, in
the case of my phone, is the little speaker that functions as the ear
piece, and I hear the King.

Hunsucker said the problem can sometimes be cured with a
radio-frequency filter that can be attached to the phone line. He also
said that if the radio signal is very strong, a filter might not be

Such is the extremely rare case when a person's mouth acts as a
receiver. The electrical conductivity of the human body can act as an
antenna. A metallic filling in a tooth, reacting just so with saliva,
can act as a semiconductor to detect the audio signal. The speaker in
this case could be anything that vibrates within the mouth enough to
produce noise, such as bridgework or maybe a loose filling.

In those cases of extremely strong radio-frequency waves, Hunsucker
said the receiver effect can be eliminated by surrounding the bogus
receiver with a grounded, copper-screened cage. Or you may choose to
sit back and enjoy the music."


Frequently Asked Questions: Teenage Orthodontic Patients (tm)

"Is there any chance that I will be able to hear the radio on my braces?"

"Well, we do not think so, but you should listen carefully to be sure.
Years ago there were reports of people hearing the radio on their
fillings. At the time, radio was different. There were only a few
stations and they were all AM. People also used crystals to listen to
the radio. The crystal set consisted of a "ceramic insulator" much
like a tooth covered by a metal piece which was like a bracket.
Crystal radios could pick up AM signals when they were close to the AM
station. People claimed to have heard the radio on their fillings when
they were standing by the radio transmitter and their mouth was
completely dry.

I have never heard of a report of someone hearing the radio on their
braces, though. Still, it is theoretically possible so listen
carefully! If you hear the radio on your braces be sure to tell us.


We just got a report of someone from Texas who can hear the radio on
his braces. Be sure to listen carefully. Can you hear the radio too?"


Radio Received Fillings

"From: (David Lesher)
Subject: supporting evidence...
Date: Wed, 8 Feb 1995 11:05:24 -0500 (EST)

The FAQ saith:
T. Some combinations of metal tooth fillings can receive radio signals. 

[n.b -- "Field Day" is an event where ham radio operators got out to a
park or the country, set up portable stations that are self-contained,
and strive for the greatest number of contacts. While its original
function was an exercise for diasters such as earthquakes, it really
is just a chance to play Boy Scout again.]

From: (David Bartholomew)
Subject: Re: Dental Fillings and Radio Frequency Signals
Date: 4 Feb 1995 13:24:53 GMT
Organization: Primenet
Message-ID: <3gvv75$> 

It's real. I attended a Field Day setup a few years ago, staged by the
Westside Amateur Radio Club in Los Angeles. They had one of their
stations inside a trailer, and the radio had an automatic antenna
tuner. Well, SOMEBODY didn't ground the thing right. I was inside the
shack about 5' from the radio when the op said, "Well, 15 meters is
dead; let's tune it up on 20." He changed bands and hit the deadly
little "Automatic Tune" button. The radio began buzzing as the tuner
went to work. Also, I let out a scream as one of my teeth with a nice
filling in it suddenly felt like a dentist was drilling in it with NO
anesthetic! I RAN from that trailer uttering obscenities and the pain
vanished as soon as I got clear of the thing. Needless to say I didn't
hang around that particular shack much during the rest of the contest.

-Dave WB6WKB 

================================================= - New Scientist: The Last Word Science Questions and Answers

Questions & answers on everyday scientific phenomena

Ghostly voices 
In 1980, my husband and I sailed from New Zealand to Hawaii and back.
Just the other day we confessed to each other that, on quiet nights in
the middle of the ocean when there was very little wind and hence very
little boat noise, we could hear voices coming from the mast. These
voices would be both male and female but you couldn't make out what
they were saying. We were both quite sober and were not under stress.
Can anyone explain this? Our mast is aluminium and the stays are made
of coiled wire.
Jenny Pollock , Nelson, New Zealand 
The ghostly voices were from short-wave radio stations--possibly quite
a few of them overlapping. The mast and the rigging of a typical small
boat are just about the right size to resonate at the frequency of a
short-wave radio signal. If two items of metal are joined and there is
some corrosion between them, the junction will act as a diode and
"rectify" or demodulate the AM radio signal. This causes an
audio-frequency current to flow in the metal.

There are several mechanisms by which the audio-frequency signal could
be converted into sound waves, including causing vibration of the
rigging as the current interacts with the Earth's magnetic field.

Sam Mulholland , Bristol  

With amplitude modulated (AM) radio waves, rectification is sufficient
to give an audio signal. That's how the old crystal sets worked. The
aluminium mast with an oxide layer or other corrosion could easily
cause rectification, particularly if there was contact with other
metals. Turning this electrical signal into sound waves is less easy
to explain, as the mast or rigging would need to vibrate in some way.

Many years ago I experienced this type of reception in the Antarctic
in a wooden hut that was heated by a free-standing stove with a metal
flue. It was noticed only occasionally and only with our own
transmissions--the transmitter and its aerials were fairly close. The
sound could be clearly heard coming from the flue.

David Simmons , Bottisham Cambridge 

The voices the couple heard were radio waves that were being picked up
by the mast and stay arrangement. Either the mast or the hull was
acting as the speaker.

When I was a child, my family and I heard radio broadcasts at nights
through our water heater. The pipes acted as the antenna and either
the heater itself, or the small room it was in, acted as the speaker.

George Siegenthaler , Norman Oklahoma

During the Second World War the same phenomenon gave rise to many
erroneous reports of the "foreign invaders" in areas of Britain close
to short-wave transmitters. Strange voices in hedgerows at night were
reported to the police or the Home Guard. On investigation it was
found that modulated arcs on barbed-wire fences were picking up BBC
World Service transmissions.

Mike Wootton , Pattingham Staffordshire 

Back in the 1930s and 1940s a super-powerful AM transmitter was
installed on an experimental basis in Texas. Local residents reported
music coming from fence wire, bathtubs and even tooth fillings.


Official Usenet Alt.Folklore.Urban Frequently Posted Legends

"This is part three of the five part Frequently Asked Questions list
for alt.folklore.urban.  This section contains a list of various urban
legends and related topics for this newsgroup.

If the story you are considering posting to AFU falls under one of
those discussed below, reconsider the posting or at least ask about it
intelligently.  Chances are, if it's on this list, it's been discussed
to death.  If you still want to post it as is, youse takes youse

Key to one liners below:
T  = 100% scientific truth
Tb = believed true, but not conclusively proven
F  = 100% falsehood
Fb = believed false, but not conclusively proven
U  = unanswered and may be unanswerable
P  = Maybe it didn't happen, but it's scientifically possible
(used extremely sparingly, where the opposite is expected,
as it could apply to just about every legend)

T. Some combinations of metal tooth fillings can receive radio signals.

(T  = 100% scientific truth)


The Misapplication of Science

The alt.folklore.urban FAQ

T: Some combinations of metal tooth fillings can receive radio signals



Urban Legends -

Television comedienne Lucille Ball claimed radio transmissions picked
up on her fillings led to the capture of Japanese spies.

A familiar plot employed in numerous television sitcom episodes is the
plight of the hapless character who, having recently undergone some
dental work (such as the installation of fillings or braces), begins
to pick up radio broadcasts through his teeth. What would you say to a
plot that involved a character whose reception of strange radio
transmissions through her fillings led to the capture of a Japanese
spy during World War II, with the incident later being incorporated
into a Broadway musical? Sounds too wacky even for an episode of
Gilligan's Island? It's been reported as a true story, once which
allegedly happened to one of the biggest stars in TV sitcom history:
Lucille Ball.

As Lucy tells the story, the events took place in 1942, when she was
filming Du Barry Was a Lady with Red Skelton at MGM, during the early
days of American involvement in World War II, when residents along the
Pacific coast of California lived in dread fear of an imminent attack
by the Japanese (especially after a Japanese submarine appeared off
the coast of Santa Barbara on February 23). Lucy had recently had
several temporary lead fillings installed in her teeth, and when she
drove home from MGM to the ranch she and Desi owned in the San
Fernando Valley late one evening, this is what she reported:

One night I came into the Valley over Coldwater Canyon, and I heard
music. I reached down to turn the radio off, and it wasn't on. The
music kept getting louder and louder, and then I realized it was
coming from my mouth. I even recognized the tune. My mouth was humming
and thumping with the drumbeat, and I thought I was losing my mind. I
thought, What the hell is this? Then it started to subside. I got home
and went to bed, not sure if I should tell anybody what had happened
because they would think I was crazy.
When she supposedly recounted the story to actor Buster Keaton at the
studio the next day, he laughingly told her that she was picking up
radio broadcasts through her fillings, and that the same thing had
happened to a friend of his. Nothing more happened for about a week,
until the evening Lucy took a different route home from MGM:
All of a sudden, my mouth started jumping. It wasn't music this time,
it was Morse code. It started softly, and then de-de-de-de-de-de. As
soon as it started fading, I stopped the car and then started backing
up until it was coming in full strength. DE-DE-DE-DE-DE-DE
DE-DE-DE-DE! I tell you, I got the hell out of there real quick. The
next day I told the MGM Security Office about it, and they called the
FBI or something, and sure enough, they found an underground Japanese
radio station. It was somebody's gardener, but sure enough, they were
It would be odd for Lucy to have invented a story about picking up
radio signals via her fillings; she was too honest and had plenty of
genuine anecdotes of her own to tell. Still, the tale is pretty
implausible, and documentation about the discovery and arrest of
Japanese spies in California in 1942 is curiously lacking. (It's also
unlikely that "Japanese spies" would have been transmitting in Morse
code, that the signals would have been received through dental work,
or that Lucy could have recognized whatever she was picking up on her
fillings as such if they were.)

Did Lucy really invent and spread this legend? According to Lucy in
the Afternoon author Jim Brochu, Lucy mentioned the story to Ethel
Merman back in 1942, and Merman had it worked into the Cole Porter
musical she starred in several months later, 1943's Something for the
Boys. Lucy's relatives claimed that Brochu made up the tale to spice
up his 1990 memoirs of afternoons spent in the company of the famous
redhead, but the story had already been published a year earlier in
the book Flappers, Bootleggers, 'Typhoid Mary' and the Bomb. Whether
this account was an invention of Lucille Ball's or something
attributed to her by someone else remains undetermined.
Last updated:   25 July 1999 


internetworkers Re: Why home phone service at all?

On Wed, 2004-01-07 at 11:43, Tanner Lovelace wrote:

Another true story involving radio waves:

"Everyone has heard about receiving radio on your braces, or fillings or
what not, and generally discounted it as an urban legend, right?  Well,
I'm here to tell you that it is possible.  My wife, Janell, while needing
a filling replaced (don't remember if it had dropped out or what) actually
received radio signals in her head.  It wasn't like anything you've heard
were people could turn their head and get different channels.  In fact,
it couldn't really be understood at all, since it was quite muffled, but it
was definitely a signal of some sort.  We figured out that it was most
likely something in the CB range rather than broadcast FM, though.  And, it
only did it a couple of times.  Of course, then she went and got the
filling replaced and that stopped it for good, so unfortuantely we
couldn't experiment
more with it, but it definitely makes a good story. :-)

Radio waves can definitely be received on tooth fillings, however I
would expect it to be AM radio waves only.  This could be AM broadcast
radio, or perhaps aircraft radio.  Most two-way radios such as police,
CB, and as you know ham radio*, uses FM.   FM radio requires a much more
complicated circuit to demodulate and it is very unlikely that a tooth
filling would have exactly the right combination of silver amalgam
filling (wire) and tooth (nonmetallic insulation) to simulate the proper
circuit.  However it is very simple to build an AM radio receiver out of
just a few basic electronic parts that can do the job of demodulating
the signal into sound waves, so I could understand how the tooth-filling
would work."


*single-sideband AM radio, as used by hams, also requires a
significantly more complex receiver circuit, so I'd be surprised if a
tooth filling could receive that too.  *grin*


I found a reference to The Discovery Channel's Mythbusters (where the
idea was debunked.)

"The Discovery Channel?s Mythbusters is easily one of the most
entertaining shows on television, and also one of the most
surprisingly educational. Premiering in January of 2003 as a
three-episode tryout series, Mythbusters became popular enough to
continue later that fall. Since then, it?s enjoyed a modest level of
success, and remains one of the most unique 60 minutes of television

The premise is simple: Adam Savage and Jamie Hyneman are two guys
determined to prove (or disprove) everyone?s favorite urban legends.
For example: could a penny dropped from the top of the Empire State
building break through concrete (or a human skull)?


Science Forums and Debate

Can you hear microwaves? 

"One thing I just saw was Mythbusters on TV. They tested picking up
radio on fillings. It is not feasible. What is likely is that
different types of fillings and saliva are acting to make little
About computer speakers, my friend had one that you could listen to
the radio on, and my aunt had a phone that played Cuban propaganda
along with the dial tone."



"Remember that episode of Gilligan's Island where Gilligan began to
receive radio signals in a tooth recently filled by the Professor?
Well, I just read about the invention of a device that makes this a
reality and offers even more! The difference is that the so-called
"telephone tooth" would, in addition, allow you to receive phone calls
and connect to verbal sites on the Internet, while also letting you
listen to music. Unlike Gilligan's case, however, the music wouldn't
be available for others to hear, but only play in your head."



TrendLines - The New the Hot and the Unexpected

Perfect for Chewing the Fat 

"MAXWELL SMART had his shoe phone. Captain Kirk had his communicator.
One day soon, we may be able to chat hands-free and hassle-free on a
tooth phone. Two British design students have developed a prototype of
a phone that would be fitted directly into a back tooth by a dentist.
This filling in your molar then would transmit sound through your jaw
bone into your inner ear."


keyword search:

radio waves tooth fillings
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tooth metal fillings radio signal picked up
urban legends tooth fillings radio waves
urban myths tooth filling and radio waves
am radio waves tooth metal fillings

Best regards,
firebird-ga rated this answer:5 out of 5 stars and gave an additional tip of: $25.00
Helpful, funny, most useful, delightful, comprehensive - I thank you!

Subject: Re: Radio signals picked up by tooth fillings.
From: forgey-ga on 30 Jun 2004 10:31 PDT
I have nothing to back this up, but on that Mythbusters show they
determined that this is not possible, but that due to some wierd
interaction between the fillings in your mouth and the acid in your
saliva you might hear something you thought was radio waves, but was
just a chemical reaction.
Subject: Re: Radio signals picked up by tooth fillings.
From: tlspiegel-ga on 30 Jun 2004 12:11 PDT
Hi firebird,

Oh my goodness... thank you so much for the generous tip!  And 5 star
rating!  And comments!  :)

Best regards,

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