Ask HN: Why does my laptop audio turn on when I log into Facebook?
I recently read about ad-sources correlating smartphones with desktops via transmitting ultrasonic tones that another device can listen for. I can't find the article now but it was mentioned on HN a few days ago...perhaps in a comment.
That's pretty vague. PC? Mac? Chromebook? OS version? Browser version?
Could be a browser extension; FB app you gave access to; malware; any number of reasons a website could access audio devices on your machine.
Signed into FB from Chrome (version 47) from my MacBook (Mavericks).
It was 6am and I had my earbuds in and I could tell they turned on. They didn't turn off until a few minutes after I logged off.
I went to YouTube just to check. A few minutes after I closed my YouTube tab, I could hear the audio disengage.
I'm wondering if it's connected to FB autoplay videos, but those have no sound.
Just did the same test and I'd say it's auto play videos.
(same setup - current Chrome / current OS X)
I turned on auto play videos, killed the browser, waited for my headphones to turn off and went back into FB - scrolled down and when a video came into view, the headphones turned on.
Even though the video might have no sound, the html 5 video element still needs to allow sound to pass through. When videos auto play without side, it's not that the video doesn't have sound; it's just that the video has been muted until you click on it.
(speculation of course; I don't work for FB)