But sosus was not really about listening. Anyone can listen and hear things underwater. Listening to a sub sounds cool but doesnt answer the real question: where is the sub? What made sosus powerful was the network to merge data from different sensors to triangulate a location. The effort to match contacts between sensors separated by hundreds or thousands of miles, using 1970s tech, must have been immense.

We have all seen sonar waterfall displays, what most do not realize is that those came before the large CRT screens needed to display the data. The "screen" was actually a printer continuously printing the output from a microphone array.

Waterfall printer display is at the 18:52 point. (Footage of these is very rare.) https://youtu.be/fJafj2o3Wo4