Alternatively, instead of complicating things by providing an extra vibration motor behind the display to use it as a diaphragm, Samsung could be approaching the problem like it did on the Note 10 series.
There, the earpiece speaker is internal, and takes the sound out by pumping it into a thin metal chamber that amplifies and takes it out via a row of minuscule openings at the very top of the frame's edge. We even know how they look like, courtesy of iFixit tearing down the Galaxy Note 10+ 5G, and you can take a gander about the miniature grill in the header image above.
As you can see, the bezels may have been shrunk even more in comparison with the already shaved-off ones on the Note 10 family. This fact will invariably bring with it some record screen-to-body ratio that even phones with pop-up cameras or dual-display devices haven't be able to muster just yet, and be a tribute to Samsung's engineering prowess.
As for the potential for Sound on Display technology, here's how it works, straight from a Samsung rep way back at the Society of Information Displays expo last year.