it is possible to use your computer sound card to monitor this stuff yourself
using Software Defined Radio (SDR) program you can use the mic input on your sound card to receive these ELF (Extremely Low Frequency) signals that are below 300Hz.
If anyone is curious ask away
here is a youtub vid about doing this to listen to signals for submarines at 24,000 Hz
https://www.youtube.com/watch?v=L2W1x6Rb9hI
it just takes a few adjustments to the settings and you're listening and monitoring 7Hz ~ 40Hz
the biggest factor in doing it well is the antenna
a ferrite rod type antenna commonly found in old radio receivers as the internal antenna works well. It looks like it sounds and is usually a 1cm x 30cm rod or longer wound with wire. Dangle it from an insulator and hook one end up to the audio input jack using the method shown on the video using an 1/8 stereo to RCA adapter with the single antenna wire hooked up to the center pin only on the RCA connector. the other wire on the rod antenna does not get hooked to anything.
Setting up SDRsharp is for another post