Dude yes!! And I believe its only heard on PC but it might also be on Xbox and all the years playing on PS2 I've never heard it.. there are other sounds that were exclusive to PC and possibly xbox as well like while going for the boating license you can hear very pronounced seagulls. Oddly enough though I have yet to hear anything in Watch Dogs 2
Sean makes his way to and through the toll gate (25¢) and onto the bridge. Cotrell follows. Directly below them, under the bridge, foghorns blast thunderous mournful moans, like a great lamenting troll, startling Sean, and his passengers, and they laugh.
The background chatter is annoying, but I have come to appreciate the way it provides context. I particularly like it when you can hear someone vocalize "blaaaaargggh!" clearly imitating the foghorn and a bit drunk.
It has been there since the bridge was built, but you don't hear it everywhere. I haven't lived in San Francisco for years, but I still remember hearing it on quiet nights. It makes me homesick.
I think there are two sets, one set midspan and the other on the San Francisco-side pier, but I'm pretty sure that what we are hearing here are the mid-span horns, with the East- and West-facing horns having different tones.