Gotta love how the media uses the word “secret” because as soon as they say it, it’s not a secret not to mention there’s lots of info on SOSUS which has been around for 60+ years.
Also The Hunt For Red October (book) was published in 1984 and featured SOSUS and what the book and movie called “SAPS” - the SONAR signal processing systems.
A lot of folks were REALLY surprised by that, given the first edition of the book was printed by the Naval Institute Press. (I have a copy)