In Small Sonorities: Material Signals, objects are driven by low frequency signal that transfers action (visible) into sound (invisible) as translation and metaphor for entanglement and interconnectivity. (remaimodern.org)
The snag is that we would need a space telescope 100 times as sensitive as any planned to find auroras within a few dozen light years, because the Earth's atmosphere would absorb the low frequency signals. (newscientist.com)
Thus the tree rings frequently contain a low frequency signal that is unrelated to climate or, at least, confounded with climatic effects such as temperature. (deepclimate.org)