Dental filling radio reception?

As noted in other responses, a resonant circuit is not mandatory, especially for strong local AM stations. I suspect anyone who has ever built a simple crystal radio (diode or traditional) in an urban area has noted that one strong local station seems to dominate the whole band, regardless of where tuned.

Likewise, there are electromechanical transduction processes that work on biological tissue. The ones I have experimented with work at higher voltages (several volts RMS), but that was to produce a sound that was audible in free air. (This was a signal generator with a paper clip on the hot lead. If you brushed your fingertip on the clip in *just* the right way, you could hear the oscillator frequency. Don't recall how the ground was connected.)

And of course the best example of a bio-electro-mechnical transducer is an outer hair cell from the inner ear. These guys have on the order of 100 mV across them, and when the stereocilia ("hairs") at one end are moved by vibration, they modulate conductance channels and the cell conducts current at the vibration frequency. That part of the system is of course going from mechanical to electrical. But in response to the changing potential across the cell, it changes its length and actually ends up boosting the mechanical input signal. As far as I know, there has been no systematic survey of other tissues to see if they have this electrical-to-mechanical transduction property, unrelated to their normal function.

So *in theory* there could be a transduction system.

My question was related to the signal level that could be present in the first place, given what I supposed is the Faraday shielding of the conductive tissue of the head and mouth. I think there must be a way to compute this, since the same issue would be involved in (for example) using conductive foams and coatings on electronic apparatus to get EMC compliance.

Best regards,

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis