Newer Echo and Echo Dot speakers can now detect people

Beginning from this week, the latest Echo and Echo Dot speakers can use ultrasound to detect occupancy in your home and turn other connected devices on and off, like lights or your Fire TV. First mentioned at Amazon's fall hardware event in September, the fourth-generation Echo and Echo Dot speakers can now emit an "inaudible ultrasound wave" to detect whether people are present in a room.

You can enable or disable this feature in the Alexa app, where you can also set up occupancy routines to use this new ability to do things like turn lights on when you enter a room and then turn them off again when the room is empty. You can also have Alexa play music or a radio station when motion is detected near an Echo device for a set time, and then turn songs off once it's gone.

The feature is mentioned under Motion Detection in the Alexa app settings for each supported Echo device, and one will be able to turn the capability on or off here.

This feature is very similar to what the newer Echo Show motion-sensing devices have, but they dependon their cameras to know if there are people in the room. Echo speakers do not have cameras, so the deviceemits an inaudible ultrasound wave and detects movement that is reflected off nearby objects before coming back to the device's microphones.

There are a number of standalone motion sensors that work with Alexa to trigger Routines, including those made by Philips Hue, Aqara, and Centralite. This new feature means that, in theory, you won't need to rely on one of these additional devices to turn on the lights or music. It also promotes Amazon's vision of the environmentally smart home, one in which your home automatically responds to its occupants with minimal prompts from them.

Anyhow, Amazon needs to put more effort into the Alexa app. Setting up routines to turn the lights on to the correct brightness based on the time of day and then turning them off again when the room is empty requires a lot of patience and a fair amount of technical knowledge.