VLF propagates out of the earth from the north pole to the south pole and then from the south pole up to the north pole. Just as every other type of radio frequency naturally or artificially does the exact same thing from ELF to EHF out of both poles.
Which means if you have the right instruments to pick on these naturally and artificially occurring frequencies then you can pick up on anything from noise to human conversations. In past week I have found that software defined radio whether it be a cheap dongle or a expensive great Scott gadgets hack RF 40. The way I did it was I have two programs that work with my USB SDR dongle one called FreeDV and Quisk where I can see what bands are passing through the area and then make contact with whom ever is using that band. Normally most people using these citizen radio bands have SSB’s but it seems with advent of more widely available technologies. SDR’s look to be the replacement for traditional citizen radio but analog will still exist alongside the digital alternative which is things like SDR’s.