The Pixel 4's silliest feature would be right at home in Google's Nest speakers and displays

I don't want to wave my hands at my phone, but I do want to wave them at all of my smart speakers

The Pixel 4 was a better phone than a lot of people give it credit for. Yes, it was overpriced, and yes, battery life on the smaller model sucked — alright, maybe it wasn't a great phone, but it was at least a very cool one. It marked a number of firsts for Pixels: it was the first with a high-refresh rate display (at 90Hz), it was the first to offer multiple rear cameras, and it was the first (and thus far, only) Pixel to offer secure face unlock. It was also the first consumer product to feature Soli, Google's radar tech. Its utility in the phone was... questionable, but I think a similar implementation in Nest speakers and displays could be a game-changer in how we interact with them.

Soli uses radar waves to detect presence and motion in a less invasive way — unlike in camera-based approaches, Soli can't see you in any meaningful way, but it's able to tell when an object is nearby and roughly how that object is moving. In the Pixel 4, this was used in a number of ways: Soli can tell when a person is nearby, so the phone knew to only show its always-on display when someone was around to see it. You could also wave your hand left or right in front of the phone to skip forward or back while listening to music. Google calls these gestures Motion Sense.

As neat as that all is, we weren't especially enthusiastic about it, even at the time. The Motion Sense gestures to control music playback were unreliable, and any battery gains to be made by intelligently powering down the phone's always-on display and IR face unlock module when they weren't needed were minimal (battery life on the Pixel 4 was notoriously poor). But these features pioneered on Pixel would be a perfect fit in Google's Nest smart speakers.

The second-generation Nest Hub actually has a Soli module and limited Motion Sense functionality, but there isn't much to it. It's used in tracking your sleep, and waving your hand near the display will snooze your alarm. You can also hold your hand in front of the display to pause media playback. That last bit is the most interesting part for me: Nest Hub Max uses its camera to offer a similar feature, and I use it on mine constantly.

I find myself interacting with the display, placed on the kitchen counter, most often when my hands are wet or covered in food; a quick gesture makes it convenient to pause media without touching the display, and it’s the kind of futuristic novelty that drives me wild. I've thought many times that it'd be infinitely more useful if I could also skip tracks in the same way (I'm very peeved that the wave gesture on the newest Nest Hub is reserved for alarms).

Aside from simple playback control, Soli's presence detection capabilites could allow music to "follow" you from room to room; if future generations of Nest Audio speakers and Nest Hub displays contain Soli modules, they could, seemingly, offer functionality to only play music in rooms where it detects a person. That might sound like a niche use case, but music playing to empty rooms is just noise. Given the time that's passed since the Pixel 4's release, it'd be nice if we could see some of the other air gestures Google once teased come into play, too — like turning an imaginary dial to adjust volume without actually touching the speaker.

Google's still working on Soli, so my dream of gesture-enabled, presence-detecting smart speakers could still become a reality. Who knows, maybe Soli will make a surprise appearance on the long-awaited Pixel Watch. Even if it doesn't make its way to future Nest speakers or Google's upcoming wearable, Soli shouldn't make a quiet exit, and I hope Google has some idea of where to integrate the technology in its consumer tech. Motion Sense is just too cool a feature to live and die on a handful of devices.