People can now be detected by some Echo speakers.
Ultrasound-based motion detection is coming to fourth-generation Echos and Echo Dots. Newer Echo and Echo Dot speakers will be able to use ultrasound to detect occupancy in your home and turn on and off other connected devices like lights and your Fire TV starting this week. The fourth-generation Echo and Echo Dot speakers can now emit a "inaudible ultrasound wave" to detect if there are people present in a room, as announced at Amazon's fall hardware event in September. In the Alexa...