Unusual times prompt unusual occurrences. A friend was watching a science museum presentation and the presenter was flustered because of a recurring loud sound. They ultimately tracked it down: a tab on their browser was playing back an eagle video. You know: normal!
It’s easy to have mysterious sounds playing from browser tabs. This often occurs because of auto-playing video on a page load, the auto-play feature in YouTube that seems to re-enable itself on my devices all the time, or pages that after being idle for a while reload themselves and start playing video you’d paused—or even redirect the browser to a new page with auto-playing video!
Whatever the cause, all major desktop browsers often a simple way to see which tabs are playing sound and quickly mute them.