Here’s another question I hear: If the device is listening for a specific wake up phrase, how do I stop others from using it?

Some users and analysts have noted the amazing sensitivity of Glass. In my own experiments I’ve noticed that it’s even responsive to whispers in a quiet room or speakers from across the room, so it is possible that someone not wearing it can activate it in quiet conditions.

Speaker verification could be added to wake up words, without hurting the power consumption. The settings can be very light to reduce false firing and keep out some percentage of unintended users, or it can be tighter for more security. The “tighter” and higher security means the higher likelihood that the right user won’t always get in, that’s why we use a “light” setting so wrong users are USUALLY kept out and right users virtually always get in. The speaker verification requires training, but this could happen in an “adaptive” fashion with use, so that the training is invisible to the user. The longer the training word or phrase the better the accuracy!