The engineers and researchers at the MIT Media Lab's Fluid Interfaces group wanted an interface that would allow a user to quietly and easily communicate with a device. Human / machine interaction had moved from punch cards to keyboards to voice commands, but often speaking out loud to a device wasn't practical. Current voice interfaces had some major issues; conversation between a user and device wasn't private, the devices were always listening and sometimes activated by an unintended word or phrase, any person could use the device, and the devices could be difficult or regulated for use on the move. Arnav Kapur, Shreyas Kapur, and Pattie Maes from the MIT Media Lab tried to use gestures and touches as inputs for AlterEgo, a wearable interface for the user's face.
The paper AlterEgo: A Personalized Wearable Silent Speech Interface was presented at the ACM Conference for Intelligent User Interfaces in March 2018. The paper discusses the architecture for the device, the neuromuscular inputs, and the results of some early feasibility tests. A pilot study of three people was done to find the best electrode positioning on the face. First, data was taken using binary yes-no signals and expanded to include around five hours of internally-vocalized text.
Wearable form design is the most interesting part of the paper for me, where requirements and considerations are outlined. The electrodes needed to stay on the face without moving, remain consistently in place between multiple uses, and allow for adjustment to achieve the sweet spot on many different users. A 3D-printed photopolymer resin band housing a brass rod acts as the support structure, designed to maximize friction between the electrode and the skin while minimizing the movements required. Next steps in the project include more data for the silent speech model, more words for the system to recognize and process, and tests in different user scenarios.
AlterEgo feels like a device that's going to be incredibly useful while at the same time setting off alarm bells in my head that the future is going to be full of weird spider-like devices hugging our faces. The project's website has an excellent FAQ section, a list of publications about the device, and the disappointing revelation that, no, you cannot be a test subject for the AlterEgo at this time.