Amazon has added a new feature for its newer Echo and Echo Dot speakers. The feature will allow the smart speakers to use ultrasound to detect occupancy in a home, and switch on/off connected devices such as lights or your Fire TV. The feature, which was first announced at Amazon’s fall hardware event in September, is now available for ourth-gen Echo and Echo Dot speakers.
Users will be able to enable or disable this feature using the Alexa app. With the addition of this feature, users can also set up occupancy routines to use the new functionality to perform tasks such as turning on lights while entering a room and turning off the same when the room is empty.
Furthermore, users can also instruct Alexa to play music when motion is detected near an Echo speaker during a set time, and then shut down the same once you have left. You will be able to find the function listed under Motion Detection in the Alexa app settings for each compatible Echo device.
This feature seems to be pretty similar to the motion-sensing feature that is found on newer Echo Show devices, but those depend on their cameras to tell if there are people in the room.
On the other hand, the Echo speakers do not have cameras, and instead the devices detect movement by emitting an inaudible ultrasound wave that reflects off nearby objects before travelling back to the device’s microphones.
While Google also uses ultrasound in its Nest smart displays to detect the proximity of a person in relation to the device, you can’t use ultrasound sensing to trigger Google Home Routines.