Edit - I'm not sure that's the same thing? The release talks about pixel based sound, the linked paper is about sticking an array of piezoelectric speakers to the back of a display.

edit 2- You're right, the press release is pretty poor at explaining this though. It is not the pixels emitting the sound. It's an array of something like 25 speakers arranged like pixels.

https://www.eurekalert.org/news-releases/1084704

But the current one is just wrong.