[jmiskovic]

Is there a name for shifting the recorded phenomena into the part of spectrum where humans can directly sense it? Or for converting signals into different medium, so that we can hear or see signals that we couldn't sense otherwise? I'd like to know the name so that I can hunt for more examples and applications.

A good example is Dwingeloo radio telescope where they convert pulsar signals into audio in realtime so that you can listen to it using headphones. Another example is playing a sound every time your runtime preforms garbage collection, to gain first-hand intuition for internal operation (like you can pick up any abnormalities in the car engine sound).

[npteljes]

In case of images, hyperspectral imaging[0] maybe.

NASA, when publishing the Sinister Sounds of the Solar System, called the technique Sonification[1].

[0] https://en.wikipedia.org/wiki/Hyperspectral_imaging

[1] https://en.wikipedia.org/wiki/Sonification

[frumiousirc]

I think this is simply using one rate for sampling and another for playback.

Another comment suggests seismic samples like these are taken at 200 Hz. That is comfortably above the rock vibration frequencies of a few Hz. If one simply plays back these samples 100x faster the result would appear as 20 kHz sampling and the signal power that was originally around a few Hz would be heard at a few 100 Hz. The audio sounds a bit higher in frequency so perhaps these numbers are not precisely what were actually used but they give the idea.

That's just the shifting. Accelerometers are used for the original sampling so there must also be some sort of pre-processing in the original sampling domain (the example 200 Hz time base) to convert acceleration information into displacement. This is a 3D displacement so then some other transform must be applied to represent the 3D vibrations with a 1D model.