When listeners pay attention to stories, their heart rates rise and fall in sync
Fake headline.  This is not the usual meaning of the word “synchronize”.  As many other commenters here point out, this makes the story a non-story.  Strictly speaking, the headline is true in that the heart <i>rates</i> “synchronize”, but not the heart <i>beats</i>, which I would think that most people would mis-read the headline as.