Here's a semi rumor here. We'll say semi rumor because this patent was indeed published by Samsung in South Korea, and does show how the S Pen would work with Ultrasound waves. On every Galaxy Note device so far, we've had the S Pen with a digitizer built into the display, which was provided by Wacom. Now it looks like Samsung is looking to transition over to Ultrasound waves to use the S Pen on the upcoming Galaxy Notes. Now there's no word on this being in the Galaxy Note 4, but I'd be surprised if it wasn't.
The biggest reason why Samsung might be going towards ultrasound waves? Well it means they don't need a digitizer built into the display, so it'll be cheaper. But also it means thinner display assembly. Which means they could make the device thinner, or just pack in an even larger battery inside. Which isn't a bad idea, actually. It's important to remember that this isn't a first for ultrasound waves and stylus'. As Qualcomm showed off their own stylus that used Ultrasound waves earlier this year. Support is built into their Snapdragon 805 chipset, which means Samsung wouldn't need any additional hardware here. We are expecting to see Samsung's next Galaxy Note - the Galaxy Note 4 - to feature the Snapdragon 805 inside, even though they did just announce a new Exynos chip last week that does do LTE. If Samsung does use Qualcomm again this year, the likely reason will be for the ultrasound waves support.
The Galaxy Note 4 is slated to be unveiled in September at IFA in Berlin, which is where it's been announced for the last 3 years. So we're just getting started on the rumor mill with the Galaxy Note 4 right now. We'll likely see a lot more rumors in the next 6 weeks or so before IFA takes off. We're also expecting to see the Xperia Z3 announced at IFA this year.