Here's how Note 10 may use Sound on Display tech to get an 'all-screen' design

Samsung will reportedly soon employ its own audiocasting screen technology called “Sound on Display,” either on the Galaxy Note 10 or the Galaxy S11, to shave off the top bezel even further compared to what’s on, say, the Galaxy S10+ (which is not much to begin with.)
Here it is on the retail NEX, in the from of a small actuator glued to the back of the OLED panel, sending its electromagnetic impulses directly to the panel which ripples the air above it to deliver the sound vibrations to your eardrum.
What’s Sound on Display?
An interesting sound-emitting display concept by Samsung got our attention when showcased at the Society of Information Displays (SID) expo last year. As you can see in the video above, the Samsung rep explains how a panel using vibration and bone conduction may negate the need for an earpiece, helping extend the screen all the way from top to bottom.
Both Samsung and LG already commercialized their sound-emitting OLED displays in phones, the G8 and Galaxy A60.
The transmission bandwidth is said to be in the 100 ~ 8000 Hz range, and, thanks to the very fine vibrations, you would only hear the sound if you put your ear to a fairly wide area at the top half of the screen, denoted with a circular symbol here.
According to Vivo, “compared to other audio solutions for bezel-less smartphones, it conserves power, reduces sound leakage, and optimizes low to high pitch sound for a better and more balanced audio experience.” Here’s what the Crystal Sound exciter looks like inside the LG G8:
How does Sound on Display work?
First off, you need an OLED display to place small exciters/actuarors behind. The LCD panels have an extra backlight layer that can’t transfer the tiny electromagnetic vibrations that the exciter pumps through the screens, using the top layers as a speaker diaphragm of sorts.
Samsung’s own Sound on Display technology works in a similar fashion – a tiny actuator or two behind the AMOLED displays. The humble Galaxy A60/M40 are the ones where this Samsung technology employed first, and this, coupled with their punch-hole display designs makes them achieve an “all-screen” front similar to its much more expensive brethren in the Galaxy family. They use just one tiny exciter behind the AMOLED display, as you can see in the screenshot from the disassembly video below.
Samsung, however, doesn’t advertise this as Sound on Display, but just says Screen Sound Technology, and with a good reason. They do have speakers inside, and the tiny screen exciter motors make the top of the display vibrate only during voice calls, as you can see in the disclaimer below. Whether or not this will be the case on the upcoming Galaxy Note 10, remains to be seen.