Happened again, this time I confirmed that a "steamwebhelper" process was causing the sound as killing it stopped the sound, this time without killing steam.
Following is output of all children of the initial steam process 6286 from "ps …
Confirmed in a pub that this has happened to several other people (>4), I believe that they were all on windows and could also mute the offending sounds (apparently by muting steamwebhelper).
Okay, so looking at the training section of NS2, I'm pretty sure that it's playing audio from the Tutorial "Introduction" video as well as the "Tip Clips" videos. Ironically when playing these within NS2 I don't have any audio for them, despite all …
Okay, so I managed to reproduce the issue, meaning that at some point (about 30mins this time) after closing NS2 (although maybe NS2 doesn't need to have been opened for this to occur) the same issue occurred as described above. I listened to the so…
So far I haven't managed to reproduce the issue again. I have never u…