[scarybeast]

Do you have any recommendations for any particular techniques or software? I'd gladly try them.

[bigbillheck]

The classical approach is a matched filter.

Here's some references: https://www.rfcafe.com/references/articles/wj-tech-notes/fsk...

http://edge.rit.edu/content/P09141/public/FSK.pdf

There's lots of matlab code floating around out there, if you're willing to try gnuradio that'll work (for example: https://nccgroup.github.io/RFTM/fsk_receiver.html), and this looks promising: http://www.whence.com/minimodem/

ETA: Audacity might be able to do it too : https://www.youtube.com/watch?v=tKNNnbgoGdI

[marcan_42]

This is how I've done it in the past, seems to work quite well on your wav file :)

https://colab.research.google.com/drive/1Zvb6bQfC3thc5-39exp...