[primitur]

I wonder if there is anything unique about this that might make it interesting to use in a sampler or a synthesizer or something .. maybe some random noises that could be generated by stroking the core, or some such things ..

[vegetablepotpie]

I doubt that storing digital representations of sounds on the cores and then stroking the cores would result in any modification of the data. You could run a wire with current next to the cores to induce bit flips, but what happens to the sound would depend on the format of the data stored on them.

You could put an inductor in or around the array, which could pick up magnetic impulses from currents used to program the cores. If you amplify the voltage coming out of the inductor and sample that, it could result in interesting random sounds.

[pjc50]

You could play with the distortion induced by core saturation, perhaps. Go full analog and run the audio directly through the core array.