Interesting idea. If you play back a sound recorded from a solid, thereby rendering an inaudible sound audible, and it re-enters our bodies through our ears, I doubt that it'd be perceived in the same way as if we'd truly felt it through our guts, bones, hair, what have you. That's not to say that your idea isn't valid for sound design and as an effective layer, but we'd be exposing the listener's ear to something they'd normally not get through the good ol' pinnae. This sensory transposition might be effective, or not...I'd think it would be really dependent on the sound source itself, the context of its use, and the emotional message one was going for.

the main effect is of course that our own voices sound much more bass-y then they to anyone outside of our heads.

Most modern sound design today are based in the way we perceive sound, not the way it actually behaves in the natural world. Bone conduction, though, almost only applies to very personal sounds like hits and such physical interaction. Other things even more influential on how we perceive sound is due to the fact of our brains subconscious ability to sort different sounds out as to not risk overloading from stimulation. Even for us lacking most of that sensorical filtering, we still choose what we wanna focus on and reacts harder on details considered more important than others.

I am very fond of contact mics in general, though my own one went belly up a while ago, but for emulating bone-structure I rather use extreme proximity from a cardioid for several reasons. For one thing, materials used as conductors rarely, if ever, follows the same characteristics as human skull-bone anyway. Second of all the entire cranium, inner ear, flesh and all, gets affected by that kinds of sounds. But most of all, a contact mic is based on piezo technology, meaning a crystalline material that makes a great addition to sound effects, but not being very fat in itself.

As with most sound design issues, this is something better mimicked than tried to be reproduced in my opinion.

I'd have to agree with NoiseJockey on this one. I don't think simply adding in a sound recorded through a contact microphone would achieve the results you're thinking of. To approach that ideal, you'd probably need to create a custom sound installation. Things like this have been attempted in cinema in the past...devices like vibrating seats, gas emitters and small speakers here and there for localized sound.

Hmm, this is definitely a cool idea. But whilst the effect of mixing in contact-mic recordings with standard recordings would no doubt create some very interesting effects, the only practical use of this I can think of would be to add an interesting spin to POV pieces.

When recording, you'd contact-mic your own head up (or the head of the subject of the POV / main character in a piece when recording their dialogue etc)! This would mainly be used with dialogue though, I guess, as our speech always sounds different to ourselves due to the conduction our voice through our own skulls. This could then help create a difference for when in "POV mode" and when not, in a piece.

However, as already discussed by others here, I think this effect would be best created manually with effects, altering EQ, enhancing bass etc (also discussed in this thread I think..!).

I think, unless you have one of your bones in contact with a surface, the effect won't be one of "realism". Wouldn't our fleshy foot-soles do the same thing as the shock mount? Doesn't mean it won't be a cool effect though; just last night i was recording some stuff w/ a hypercardioid+contact mic. Mainly for a surreal effect, though.

Sound recordings don't sound like what we really hear because our hearing mechanism is insanely sophisticated. I'm no psychoacoustics expert, but i think a lot of that comes from our brain/ear's ability to localise and focus on specific sounds.

I also think that, while these discussions are fun, we can say "could/would/should" all day, but there's no substitute for empirical experimentation. So give it a shot and post results!