thanks for sharing your insight, coderman. i have an additional comment on a single point... perhaps i misunderstand it, though must 'resonance' be audibly acoustic, and would a SCIF actually defend against "vibrations" at all frequencies. what is referenced is the pairing of vibration in resonance, fundamental to quantum physics if not mistaken, whereby two identical entities can vibrate in unison, at a distance, to include at opposite ends of the universe, seemingly so if this were involved, not necessarily sending human audible soundwaves, though that sympathetic vibration (as one string vibrating influences another, say) or other (wireless power of Tesla, though i do not know enough to make the case) could potentially function beyond a SCIF barrier or wall. for instance, if having a tuning fork on the inside and a tone naturally generated else also electromagnetically sustained on outside of the SCIF, such that a vibration or specifically paired resonating condition would under normal circumstances exist, vibrations causing other vibrations -- though while inaudible or outside normal hearing ranges, is it by default true that a SCIF kills off that paired vibration, else would not quantum effects cease to exist in the materials (atoms, molecules, particles) inside of the SCIF and have the power to detach them structurally from space-time even. i tend to think the tuning fork would vibrate inside the SCIF moreso than not, if it is explored beyond ordinary channels. just a guess. perhaps though because i do not actually have any actual knowledge of these things, nor the science in its depth or breadth, that this is readily taken care of and accounted for in a security context. either way it would not be surprising to me, that such conceptual gaps may exist in auditing or they may be undocumented yet accounted for.