The next time you see a software engineer shaping silent words with their mouth, you may have to think twice before asking if they need a mental health day – they might just be wearing a pair of smart glasses that let them talk to their computer without uttering a sound. Subvocal is a Y Combinator-backed startup aiming to produce these glasses, and already has working prototypes to show off in YouTube videos, including one with YC partner Dave Lieb trying them out and being impressed enough to offer funding. The headset isn’t what the final version will look like, the company notes, which is good: The demo headset is obviously 3D printed and far from fashionable. Once the final product is available it should look a lot sleeker, based on mockups on the company’s website. It’s not clear when they’ll actually be released, though the preorder page says it’ll be sometime in Q1 2027 at an early bird price of $499. It’s not clear what the final full price will be. As for how the glasses work, the founders, Georgia Tech computer science students Aarush Yadav and Arnav Kumar, explain in a launch post on YC that the device uses low-powered radio waves projected from the glasses toward a wearer’s face. Those waves are distorted by muscle movements and the change in a person’s face shape as they speak or simply mouth words, which the duo said can be picked up and translated into written text. “We started working on this about four months ago after building the first version at a hackathon,” the pair explained in their YC post. “Since then, we’ve gone from a table full of electronics and antennas taped to our face to a semi-portable board and sleek glasses that can decode open-ended speech at 200+ WPM and a reasonably low error rate even at a small dataset scale.”…